I'd like to point out something I think maybe Striker is not considering.
It's obvious the op is new to this game, thus new to the community, and how it operates. That said, I play many other games, as most do, and in some of those, I have come across favorite servers that like to "spread the word" about their servers/sites, and thus encourage wearing the tags. Trashed Gamers is one that springs to mind for TF2. Over the years of gaming, I've worn support tags in this fashion. That way, when I see another bud ingame and he asks "What's \TG/ stand for?" The intended effect has taken place, and they are p1mped, as it were.
You sound like this isn't a possibility in your list of possible explanations, and I can attest that it is. In fact, my current nick I've only been wearing in tribute til a favorite cartoon character is brought back to life.(Kinda like a black armband) Once the new eps are out, and he's back...I will probably return to the old faithful nick. My point being, that nick wore the \TG/ tag for about 8 months in support, but I wasn't part of any kind of clan. Just hung on a cool server is all, giving props. Not every gaming community is regimental, and reality is rarely black and white, so there are going to be some new bloods that may seem suspicious to your point of view, but just remember, not everyone is an asshat out to make your life miserable. I used to run a UT2K4 server for awhile and know how hard it can be to keep a clean pub going so I give props to you guys for that!
I just have this feeling this was an honest mistake, a dude screwing around, maybe a lil excited is all.
Although I have been fooled before too...