The past few days I've had 4 or 5 characters wiped out. I've been wiped when I log out for the night on a server then click play the next day to log onto that server. I have also been wiped switching to another server when trying to join a few friends on a server that we have played on before that, did not wipe our characters.
It appears to be randomly happening to some people, like myself and one of the people I play with, and only in the past few days. I was thinking that the servers may not be white listed, but some of these servers have been up since before Christmas.