If we ever "lose user account data" and ask you to sign up again (or remove account functionality entirely), then you should not trust this site any longer.
If this were to happen (extremely unlikely), then this site would now be an FBI honeypot.
You would also likely start to see "mods" (not us) encouraging all to post violence.
I believe you can trust this site for as long as your user accounts work, which will hopefully be forever.
Keep in mind that to verify whether your user accounts do work, you also need to check whether an incorrect password doesn't work.
From a young age, my grandfather taught me that the only good communist is a dead communist. He truly hated communists with every fiber of his being and would be beside himself with rage if he were still alive.