well i was wondering when the trolls would show up we got one guys lol, and please asking me if am twelve, why don't you rethink about posting something more helpful instead of making your self look like a fool. well than again it seems from the comment you posted you got nothing to do. you know theres lots in this world to do instead of criticize others just a little tip to be more like a grown up. now think hard who's the one thats twelve now?
and thanks all of you for the none troll answers you gave me.
To be completely fair I nearly ignored this post because of the way the OP and title was written so I have to forgive Originalbadboy for his comments. Your response here made me want to respond yet I still have a few doubts.
Anyway, putting tone aside the response that I was going to give:
The Developers noticed that people were not playing the interdiction mini-game, everyone was submitting and boosting straight away back to supercruise. Originally NPC's wouldn't follow and it'd be a 100% easy way to get to your destination without too much hassle.
Their response was to make NPC's respawn behind you and "chase" you through the system unless you do something to actively stop them.
Things you can do:
-Evade in the minigame
-Kill the NPC
-Jump to another system and back in
-Drop cargo
If it's police chasing you then you also have the option of dropping into USS/WSS/SSS and hoping that you get some pirates, if that happens generally the police ship will engage them and usually die fulfilling option 2 on the list above.