That's still not your concern or your problem. You're not internet Batman. Opening up yourself to criminal liability for someone else's site is insane.
Yeeeeah, that's not how it works lol. Anyone who does offensive security for more than 5 minutes understands how little protection they have. And true anonymity is much, much harder than you think.
If you act in certain ways, you will probably not get in trouble but I have a lawyer on retainer for a reason lol
The harsh truth is you aren't protecting anything by doing this, because you can't control how (or if!) they fix the problem. All you're doing by accessing the data is for-real committing a felony, and that is an incredibly stupid thing to do.