Note: This howto is not working always and can have unwanted side-effects.
So lets get started. You are normal user on dswp and you see some teammate standing in snipe mode and not moving for few minutes. You want to improve gameplay for other people so you decide to somehow stop his camping berserker.
1) Try writing him to stop camp. If he has at least little brain he can stop camping, if he understand english, but this was still not tested unfortunately and probably won't work.
2) Stand in line with his weapon blocking his view. You get his attention and can take appropriate actions. THX BEH for this one i forgot about it.
NOT-RECOMMENDED: cuz its against the rulez
3) Kick him. You can kick players when you have knife, nade or pistol in your arms. See if he returns to his position or start moving.
4) Attack him and provoke him. If he knows about about ban from tk-ing then its bad and it wont work. If he doesnt then provoke him always as he start camping maybe kill him too once (Warning: Don't do to him too much damage cause you can get banned too!), so he start tk-ing you and finally he will get Ban for 2 minutes.
Note: This can have unwanted side-effect, when he start tking other players, and thus your attempt to improve gameplay failed. If he dont get auto banned i recommend using !admin <reason> to get some help from admins.
GL and HF without camperz..