Take down everything you put on the Internet, burn everything you wrote, exert your right to delete personal information everywhere you have such a right.

Unfortunately, I'm afraid that in my case I'd have to at least nuke Facebook's servers. I used not to worry about possible future eldritch abominations at all because I thought if I saw them coming I could just guillotine my head into a fireplace or something, but now that I realize that they could likely still reconstruct a sufficient-fidelity copy of me, I do worry a little about not pissing them off. Unfortunately I barely have any idea about what would piss them off, so all in all I don't behave that differently than I used to, as per the standard atheist reply to Pascal's wager. Also, I don't think such abominations are that likely.