The kind of lawsuits you could end up being involved in simply from owning a copyright are similar to those you could end up being involved in for receiving shares of stock in a publicly held corporation that never actually pays any dividends - i.e. only those that are inherent in any kind of property ownership.
There Would Be No Criminal Or Tort Liability
If by "can I get in legal trouble just for the simple fact of owning these copyrights? . . . please give legal precedents where people have been somehow punished for just owning a copyright[.]"
Normally, when you use the term "punished" you are thinking about criminal or tort liability.
If, by "legal trouble", you mean can you have criminal liability or civil liability for wrongdoing in tort (i.e. for a civil wrong), the answer is that you probably can't get in "legal trouble."
I can't think of any way that mere ownership of a copyright could give rise to that kind of liability in the way that you might have to be concerned if, for example, you owned real estate that wasn't maintained and caused an injury to someone.
You Could Still End Up In A Lawsuit
But if, by "legal trouble", you mean that you can't be legitimately made a party to, or involved in, a lawsuit that doesn't allege that you are personally at fault, the answer is that you probably can get in "legal trouble."
I'll provide some examples, although not necessarily specific cases where these things have happened, because they are largely self-evident. Instead, I indicate what my personal experience as a lawyer has been with each kind of situation.
For the most part, the legal principles involved would be general to pretty much any kind of property interest in anything and are not really specific to a copyright in particular.
But, because it is a copyright rather than another kind of property, in the U.S. at least, the lawsuits would have to be brought in federal court, rather than in state court, in some of these cases, because the federal courts have exclusive jurisdiction over cases related to the validity, registration, and enforcement of copyrights.
You could also be subjected to a subpoena because as a copyright owner you have access to, or might have access to, information that is relevant for some other lawsuit or criminal prosecution.
The cases where you could get into a lawsuit basically fall into the following categories:
Disputes Over Who Owns Or Should Own The Copyright Or A License To Use It
The author leaves you the copyright in a Will, but the author's heirs are convinced that the author was mentally infirm and sue to have the Will invalidated. You have to be involved in the lawsuit because you were one of the beneficiaries of the allegedly invalid Will. (I've handled half a dozen Will contests).
The Will could also be invalid because the author had a contract or divorce settlement requiring the author to leave the copyright to someone else and the author violated that contract. (I've handled a case with this fact pattern, although involving real estate rather than a copyright.)
Unbeknownst to you, before the author's death, the author sold the copyrighted work to someone else and they sue you in a lawsuit intended to establish that they own it and not you. (I've handled cases similar to this involving water rights.)
Unbeknownst to you, before the author's death, the author licensed the copyrighted work to someone else and they sue you in a lawsuit intended to establish that their license is still valid. (I've handled cases like this involving leases to real estate.)
Unbeknownst to you, the author obtained the copyright for a work that was actually written by someone else (or for work that was done "for hire" while working for someone else whom they had agreed would own the copyright). As the current owner of the copyright you could be sued in an action to have the author's copyright invalidated. In a variant of this scenario, the author could have omitted a co-author of the work when filing for a copyright and the co-author could sue to be legally recognized as a co-author. (I am handling a lawsuit like that right now involving a copyright.)
Suppose that the author got divorced shortly before death and didn't disclose the existence of the copyright in the divorce action. The author's ex-spouse could sue you to recover all or part of the copyright that might have been awarded to the ex-spouse in the divorce if the existence of this asset had not been concealed, perhaps under a legal theory known as "constructive trust" (which would mean that the legal fiction that you were holding this copyright in trust for the true legal owners of it to be determined in the future, as a result of the author's wrongful conduct, would be utilized). (I've represented a client in a divorce where this remedy was obtained by a party.)
Suits To Gain Ownership Of The Copyright As Part Of Debt Collection
Suppose that the author was subject to a tax lien before the author died for unpaid income taxes, and the author's estate does not pay off that tax lien in the probate proceeding in which you receive the copyright. The taxing authorities could sue you to enforce their tax lien to collect the author's unpaid taxes. (I've represented people in income tax lien cases, although never one where someone ended up dying before the collection could take place.)
Another kind of taxes that could give rise to a tax lien on a copyright would be those arising as a consequence of the author's death. In the U.S., that would usually involve estate taxes. In Canada, this would often involve capital gains taxes on increases in the fair market value of the copyright that arose during the author's lifetime. (When I handle probate cases, I consider this possibility and have published a couple of articles on liens in probate cases.)
Similarly, if the copyright were used as collateral for a loan that was unpaid at the author's death, the lender could sue to seize the copyright in partial payment of the loan. (I've handled cases like this involving real estate and ownership interests in companies.)
Suppose that the copyright had genuine economic value and the author gave it to you at a time when the author was insolvent (i.e. had debts greater than the total value of the author's assets and the author was not paying the author's debts as they came due). A creditor of the estate could seek to set aside the transfer to you in what is known as a "fraudulent transfer" lawsuit in order to seize the copyright in order to collect a debt. (I've litigated fraudulent transfer lawsuits involving other kinds of intellectual property, although never a copyright.)
You could end up being involved in some sort of "legal trouble" because you could be subpoenaed to provide information that you have as a result of being a copyright owner.
Still, this is really no different from the risk you can have of being subpoenaed to provide information related to all many of things that you know about in your daily life that could be relevant to a court case, for example, knowledge you involuntarily obtain when you witness a car accident, or run a credit card transaction for someone that could provide the customer with an alibi in a murder case. (I issue subpoenas all the time in civil cases and routinely represent people who have received subpoenas.)
In these situations, you could be required to provide records or show up to a deposition or trial to testify at a witness, with only minimal compensation, even though no one is trying to impose civil or criminal liability of any kind on you personally. Still, this legal obligation could be a significant economic burden to you that you can do nothing about but suck up and comply with.
But, if you failed to respond to the subpoena, a warrant could issue for you arrest for contempt of court and you could be incarcerated or fined until you complied with the subpoena, and of course, if you lied while you were testifying (or at least, a prosecutor and judge believed that there was probable cause to believe that you were lying during your testimony), you could be prosecuted for perjury. Obviously, in these cases, the civil or criminal consequences would be due to your own personal misconduct in connection with a court case and not your ownership of the copyright itself, of course.
For example, suppose that the author's son was getting divorced. He or his wife might subpoena you to produce records such as the copyright transfer document, to prove that the son didn't inherit that asset, to prove that it isn't an asset of the son in the divorce. (I've had cases where issues like this are litigated, although not yet involving a copyright.)
As another example, suppose that the federal government suspected the author and daughter of being part of a money laundering scheme and was prosecuting the daughter for this crime (the author, being dead, wouldn't have to worry about that prosecution). The daughter's defense attorney might subpoena you to testify in court regarding the fact that you received the copyright as a gift rather than purchasing it, and that you weren't collecting royalties on it, in order to prove that the copyright wasn't being used as part of the alleged money laundering scheme; or the prosecution might call you to testify to the same information because the author had been reporting royalties from the copyright on his tax returns when in fact he hadn't been receiving any royalties and the money he received was really from a cocaine dealing cartel. (Creating paper trails to make it possible to disprove money laundering allegations if they were ever made is something that lawyers involved in business and estate planning and asset protection planning matters, like me, spend a lot of time worrying about, even though we rarely end up actually litigating it in the end.)
Footnote: Some Extremely Unlikely Extreme Privacy Cases
There are extremely rare cases in which the mere public acknowledgement of the existence of the copyright could have national security or trade secret implications, and you could be sued, or subject to legal action or threatened legal action of some kind in order to suppress public knowledge of the existence of the copyright.
For example, suppose that the name of the work was "A User's Guide To Cracking The Chinese Military's Nuclear Weapon Control Codes." Furthermore, suppose that the author was a former employee of the National Security Agency (N.S.A.) which is the spy agency that secretly cracks foreign government's codes. In this situation, you could probably be subject to secret legal action to put a gag order on the existence of this work. This is because if China knew that someone in the U.S. had cracked their nuclear weapon control codes, they would change them and this would impair U.S. National Security. (As a mathematics major in college I discovered that a significant number of PhD mathematicians in certain specialities related to cryptography end up being basically coerced to work for the NSA because their research is classified for national security reasons, so they have to get paid a decent salary to work for the NSA or never publish their work which deprives them of an ability to make a livelihood (e.g. as a professor or business consultant) using their knowledge - its a running source of dark humor among advance math students contemplating graduate school studies. I also have many estate planning clients who work for intelligence agencies, i.e. for spies, who have to keep certain information secret for national security purposes.)
Similarly, suppose that the name of the work was: "A Computer Program Designed To Utilize Backdoors To Encrypted Fortune 500 Company Databases Pursuant To Section 324(b) Of General Software Corporation's Service Contract Which Nobody Ever Reads", and the author was a former employee of General Software Corporation that used this backdoor for its own selfish business advantage contrary to the client's financial interests, which was legal because corporate software clients authorized this in an obscure clause of their standard service agreement. Perhaps access to this backdoor is actually the source of most of General Software Corporation's profits as it actually barely breaks even on its code writing and maintenance work. In this situation, General Software Corporation could probably take legal action to put a gag order on you to protect their trade secret, because if this trade secret became public, its value would be destroyed because the companies affected would shut down this valuable back door. (In my practice, most of the trade secret disputes involve living people in the legal marijuana industry, but if one of them died, this kind of thing could come up.)