SWAT4 community was severely hit this week. GameSpy service, that is necessary to use the in-game server viewer in all game versions has stopped working for this game. Though there are alternative ways to query and join servers, this is the default one used by most users. Same thing has occurred several times in the past, with breaks lasting up to couple of days. We cannot be sure if this time it's for good, as there is probably no official reaction on whether it is a temporary technical problem or the real end of support for SWAT4. Hype in the community has started and there are several initiatives related to this issue.
Petition is running at this website with the aim to achieve 1000 petitioners. The goal is close but what happens then is pretty likely nothing at all.
An xfire group was created by {KL}Stasek with the aim to make list of servers so you can easily join them using xfire. You can find it at swat4members. However the group has a limit of 30 servers so this work-around will not be perfect. Creating more groups, for each game version (or even game mode) would solve this, but comfort of such solution is poor.
As another option, you can use GameTracker list of SWAT4 servers to check which are online. As you can see, only less then 40 servers remained alive. It seems, that servers running MarkMod are not working at all. Some other servers were stopped as their managers find them not worthwhile to run while this problem remains.
If you got more info or ideas, pls share. But do not post anything that is not 100% sure, as I have read plenty of such texts elsewhere.