When I'm starting up emacs in a terminal (eg in xterm) I'll get the very
annoying message:

** (emacs:6471): WARNING **: Couldn't register with accessibility bus: Did not
receive a reply. Possible causes include: the remote application did not send a
reply, the message bus security policy blocked the reply, the reply timeout
expired, or the network connection was broken.

According to google it could be fixed by setting

NO_AT_BRIDGE=1

in /etc/enviroment or .profile.

Which might be, but still raises the question why I have to do it manually...