If you click the translated text you'll be able to edit it and send it as an alternative translation.
So if you should supposedly be able to make those messages yourself, but I just tried it and it didn't show up when I checked it on my phone, so I'm assuming that either:>it'll only change if Google approves it>it'll automatically change after N people sending the same edit
But if what you said about personal information is true, I don't know if googlefags would risk being sued, so the latter makes more sense.
So my theory is that the nonsensical translates are some sort of encrypted messages and people are proxyfagging to get them to actually show. Idk why though, if they have to get something across without being identified they could probably use something less botnet-y than Google, because I'm pretty sure they have all that shit logged, and there's also the fact that it's public and anyone can stumble upon it like you did.