Rated 1 out of 5 stars
DO NOT USE !
I agree with the security issues.
Firefox was stopping working after some hours of surfing.
I found out (with netstat) that a lot of connections were stuck in the state CLOSE_WAIT to *.clients.your-server.de (on port 443, ie https), so firefox couldn't open a new connection.
Disabling Show IP and the shady connections are gone, and firefox rules again.