For appr. two days now Google seems to have problems resolving the IP of the Facebook server where the profile pictures are hosted. This results in a massive slowdown, loss of connection, timeouts etc. on every Facebook page that accesses this server.
To fix this append this line to your hosts file:
This will circumvent your DNS servers and make your computer access Facebook’s profile picture server directly.
However, since this is likely a temporary problem (at least for me it occurs from 6pm GMT til next day’s noon) I didn’t include it in my secure hosts file, yet.