Does anyone know the best way to handle the Tanks? Just blast them to death, and try not back yourself into an ackward situation? I once backed myself into the stairway fire while fighting one in the Red North line tunnel lol
[OcUK] .kiet
If you can, set them on fire with either molotov or gas cans, takes them down very quickly. Failing that, try and get to an open-ish area where you can spread out as a team (though obviously dont get in a position where the tank is inbetween you and a teammate ;P).
Other than that, it is just a case of blasting away at him, if he knocks someone to the floor and starts beating them, then you can get in close for a couple of shots with the auto-shotty or hunting rifle, though can be risky.

but i've been invited to the group.. played on one of the custom servers with campaigns a bit annoying that you can see where you can climb as a zombie 

