It really annoys me people can walk right through me.

[MrBloodworth]

Gets annoying after a while.

You hunker down for a shot and some dude walks right through you and in your line of fire. + Grief points

Or,

Some opponent walks though you while "Quick knifing" and never slows a beat. You are dead.

Or,

Your max is blocking a doorway or top of stairs, but it stops no one. They walk right through.

ETC..