Since the server is the host (or your computer on SP), if you do take down the server, you are going to upset someone.
Believe it or not, scouts (especially for Advent) can be quite effective against LRFs. Just be carefull, because they get owned by any other ship type (although they can retreat really fast). Besides, scouts require no mil labs to build.
Also, scout rushing Advent so they can't build their 3 mil labs is a very effective strategy. Just make sure you have a fleet to back them up a few minutes later.