FC6 - write disabled

[Aaron Pohle <aaron.pohle@xxxxxxxxx>]

Hello,
i would use write to communicate, but write is disabled:
aaron@tux:~> write testuser
write: testuser has messages disabled

testuser@tux:~> mesg y
mesg: error: tty device is not owned by group `tty'

How can i enable write.

Thanks,
Aaron