Facebook friends offline/not visible started today

[Mark Doliner]

Hi Rocco.

This probably isn't something that Pidgin can control.  Pidgin simply
displays the buddies that it is told to display.  In this case it
sounds like the Facebook XMPP server is failing to send to Pidgin
presence information for your roster.  There probably isn't anything
we can do about it.

I'll add that I think some people experienced a similar problem
another time within the past week or so, and I believe things started
working again after a few hours.