Technically, fake picture and data won't hide your real data from Facebook if you've uploaded it before. FB definitely keeps backups of their entire db from different time points - day, week, year, 3 years, likely on tapes and disconnected from network. This approach helped Google to recover thousands of accounts recently. I for one don't care much, but if you do care and even more so if you have reasons to care - any big non-anonymous site with registrations is a big no-no.

Here at Unity you see more can stay anonymous and we don't store payment details either - that's paypal job. I guess this is as good as it gets for a non-conformist registrants.