Three Triggermen attack me every time I go too the market. While I dont mind collecting their loot, I fail to see why the guards do absolutely nothing in regards to this. All the merchants run for cover and the guards mill around dong zero. Does anybody else have this going on?

Yea. That happens because of http://fallout.wikia.com/wiki/Malcom_Latimer

He pays off the guards so they stay out of it--presumably.

You can stop the attacks if you either pay him 2000 caps or kill his rich ass.

Edit- He's trying to get you killed since you killed his son during the Diamond city blues quest.

That's Commonwealth justice.

My companion would always kill them for me but they eventually stopped attacking me after a while.

I used to look forward to the warm welcome.