There is some lawful controversy as to whether obtaining data on a webserver is simply accessing public information on the web or whether it was through "hacking". A savvy computer user might be able to access a lot of files on a webserver that was not intended to be accessed by the server admins. Is finding access to these files a form of illegal hacking or are they publicly accessible?
Part of the issue in determining the legality of this is that a lot of people in law fields aren't technically savvy enough to understand the difference between hacking and simply viewing public web addresses. As a result, you could encounter lawyers who think you're stealing their personal databases.
On the bright side, because you've found these SQL databases indexed with Google, it's much more clear that these SQL databases have been made public. If you're at all concerned that the lawyers you would be reporting this to could mistakenly turn on you then you might want to send this information to them anonymously.
Remember, anyone can be sued for just about anything. And with a strong enough legal argument and a weak enough legal defense, anyone could win a lawsuit in court.