-To mock/insult/kill a Paki bastard.
-To cause a Paki great embarrassment/torture/pain.
-To pay back a Paki the same way he does by beheading innocent people and blowing himself up.
This should be used in context to hate crimes against Pakis.
"Hey Paul, did you hear there's a new Paki on the street!"
"Oh yeah? Well mate, ITS TIME TO POP-A-PAKI!!"