Microsoft - XBOX360, etc.
You just have to practice! You're playing with seasoned neck-beards who take their gaming very seriously. God forbid you fuck up once in a while.
Seriously though, I wouldn't worry too much about it. From what I've seen, online gamers are a very fickle bunch, but you'll eventually find some people who just want to play for fun.
This has nothing to do with an FPS, but just a story about the obsessive nature of some online gamers. I have a friend who lives and breathes Warcraft, and is a tank for a guild. He wasn't able to raid one night, because the internet lines in our area were being serviced. The following night he logged back in for the raid and was verbally destroyed by the "guild leader" for not finding another way to participate, and "letting the team down". Of course, he sat there, took it like a bitch, and for his "punishment" he had to send apologies to all the other guild members for not being there for them. Fuck that.