But really now, it is gun game, not regular. Gun game is supposed to be fast paced, there should at least be a rule about not camping in your spawn when the round starts. It is pretty pathetic to wait in your spawn until the enemy eventually gets there. At least go into the map if you're gonna camp. Some maps are small, but people can always get at least somewhat out of spawn.
While this is true, crazy, this is not the topic. Our rule in place is "No excessive camping". It has been a large source of debate since deadeyedennis was active. (I hear he still lurks, so here's your shout out!)
The safe route, is exactly what 0wns said. It is certainly excessive to delay the round whilst camping, and so action will be taken at that point.
But as this is an ambiguous rule, I don't tend to take action against serial offenders unless it starts to empty our server, though I do berate or humiliate campers verbally.