People online usually use it to block door entrances with barrells etc, as you shoot the barrels and they fall over in the door way, put a few together and people can't get in without shooting them again - which reveals where they are on the map.
On CSS, CS_Office is a good map. The terrorists have hostages in an office building, if you choose to be CT (Counter-Terrorists) you have to storm the building and rescue the hostages by leading them back to the rescue point. However, you need to protect the hostages as they can get shot too, so you need to work as a team with someone infront and behind the hostage rescuer to clear the corridors.
If you are on the terrorists team, you have to obviously have to stop the CTs getting in. In the boardroom the second set of hostages are kept, as a T you can throw a grenade behind the filing cabenets in the store room which explodes throwing the cabenets blocking the door entrance. You can then wait and unload into the door way to stop the CTs.
Fun Fun.
