This question is an expansion of Hacking devices to unlock features: Legal or not?

I'm currently in possession of a laser measurement tool called Bosch GLM20 which is their most basic model. As per the manufacturer website it doesn't support several features of more advanced models: area/volume, indirect measurement, addition/substraction. These features are purely implemented in software and don't require additional hardware to function.

Would DMCA prevent me from taking the device apart and flashing my own custom firmware on the device that supports these features? The code will only utilize open source software and my own code contributions, so Bosch would not be able to claim copyright. The device in question is luckily simple enough that this is feasible for one person to do.

On the one hand, I will modify software to get access to features I didn't pay for. On the other, I'm flashing my own software onto the device and not using any copyrighted code.

  • 1
    Making a comment because I don't really know the standards for answers on this site. If you're modifying the existing firmware, even though the code you add to it would be open source, you'd likely still be making a derivative work of the firmware, which is copyrighted software. If your firmware is a full replacement, then that wouldn't apply. The other thing that sometimes gets in the way of modifications would be the DMCA anti-circumvention clause, which I suspect you have in mind, but that clause only applies if there's an "effective measure" in place to stop access to copyrighted material.
    – LjL
    Nov 1, 2021 at 23:52
  • So without some kind of encryption in place to prevent you from "jailbreaking", to borrow a term sometimes used in this context, that clause doesn't come into play, and if there is some very basic anti-tampering mechanism that can also be bypassed without special knowledge, it also (arguably?) wouldn't apply. So I predict that in this case the copyright on the firmware might be a much bigger legal issue than the anti-circumvention clause.
    – LjL
    Nov 1, 2021 at 23:54
  • Your claim of being able to do this full replacement without using any Bosch-copyrighted code seems a bit implausible to me because on a quick search there don't seem to be any open source firmwares for those devices. What I did find is that people have decompiled the original firmware since it's apparently an Android one. To be legal new firmware "from scratch", you'd have to follow en.wikipedia.org/wiki/Clean_room_design Nov 2, 2021 at 10:31
  • 1
    @Fizz not necessarily. Ideas/facts are not copyrightable so looking at decompiled code to learn from which register one needs to read data and in which format would not result in a copyright violation if implemented independently. Nov 2, 2021 at 15:56

3 Answers 3


Yes, it's legal

In the US (and since 2020 ), there is no patent in a tangible product once that product has been sold. This is called the exhaustion of rights or first-sale doctrine. Once it's sold to you, it's yours.

So you can modify that object for your own use, to integrate it into another product, or even to onsell. You can't make another one from scratch.

As you say, there are no copyright implications because you are not using or modifying anyone else's code.

There are no DCMA implications because its your computer and you can give yourself permission to access it.

  • Could you explain your last point? Owning an item doesn’t grant access to all intellectual property embedded within that item, does it? Nov 3, 2021 at 2:33
  • 1
    It depends on the modification, IMHO, particularly if you resell it. If you modify a game console so that it can play pirated games (i.e. remove some check that the console mfg. added) that would be quite illegal under the DMCA, and basically exactly the kind of scenario that the DMCA was designed to prevent. Nov 3, 2021 at 18:33

It used to be illegal for sure. The DMCA originally included this phrase:

No person shall circumvent a technological measure that effectively controls access to a work protected under this act.

Then in 2010, the DMCA was amended. The current version exempts smartphones, tablets, and other all-purpose mobile computing devices from that clause. However, unauthorized modifications probably violate the products terms of use and void any warranties. It is also illegal to sell or distribute those modifications, or the tools used to make such modifications.

To your specific question, the suggested actions are unfortunately still illegal because the tool in question is not an all-purpose computer. Even if you don’t copy the original code, merely gaining access to it violates the DMCA.

Though between you and me, as long as you don’t distribute or sell any modifications, you’re probably ok ;)

  • 3
    The important words are "a work protected under this act." DMCA is a copyright act, that punishes attempts to get around copyright controls. Installing your own firmware is not a copyright violation, as it does not copy another (unwilling) person's work. There is no copyright on hardware itself, so it is also not derivative unless you're acquiring the manufacturer's source code and adapting it. Nov 2, 2021 at 7:07
  • And the firmware code of this piece of hardware is, for legal purposes, considered copyrightable literature. So any program that gives you access to modify or even read the code is banned by the DMCA. Nov 2, 2021 at 11:45
  • 1
    From the way I read the question, the wording "technological measure that effectively controls access to a work" does not apply. It sounds like a person wants to add additional features to a device which does not currently have those features. There are other ways of attaining those features (from the manufacturer's software), but the features are not locked. The question makes it sound like the features are absent. There may still be a question of copyright (because they want to add software to the device), but those questions are not related to DMCA.
    – grovkin
    Nov 2, 2021 at 14:34
  • 2
    Although those features are not currently on the tool, there is still source code present. If any of your technological endeavors give you access to that (copyrighted) source code, you have violated the DMCA, even if you don’t actually copy or modify that code. Nov 2, 2021 at 17:49
  • 1
    Gaining access only violates the DMCA if the manufacturer put some 'technological measure' in place to prevent access (for example setting a readout protection flag in the microprocessor or encrypting the code). If there is no such measure in place, then looking at the code is not a violation. If there is such a measure in place, then the OP does not typically need to have access to the code in order to instruct the micro to simply erase itself (which would typically both clear all the code and remove the protection - since there's nothing there to protect anymore).
    – brhans
    Nov 4, 2021 at 15:16

I think it depends what those features are exactly. As you described them, it is probably legal given that Texas Instruments "dropped the stick" (circa 2009) and did not pursue in court people who posted their calculators' firmware keys after initially sending some DMCA notices.

On the other hand, Sony did pursue Hotz and friends in court (2011) and won TROs, while the case was eventually settled with Hotz promising not to hack any more Sony devices (ever). I suspect a substantive difference between the Sony and the TI case is that the firmware hack on the PS3 would have allowed pirated games to be played, whereas there was no such 3rd party software [piracy] at stake in the TI case, as far as I can tell.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .