this mass comeback is really strange.
maybe somebody found an old dump with PWs and all the old are used now.

somebody should find a similarity between all the accounts.
date of registration?
last login before the comeback?

thanks to the colour:

augustocroppo - woke up
https://bitcointalk.org/index.php?action=profile;u=50315

Narydu - woke up
https://bitcointalk.org/index.php?action=profile;u=21434