If you're bored, then you can troll in NCR by this way, you'll kill 2-3 people every few minutes by this way and you may die by laught, because that's damn fun, I had tears in my eyes because of laught when I was doing that:
1.
1) Get a merc/slave, put him to grid far away from other.
2) Get long ranger weapon like hunting rifle, etc.
3) Have low SG% skill, so you'll have 5% to hit and will almost always miss.
4) Shout "AAAAAAAAH <Name> IS UNPROTECTED!!!11 KILL HIM".
5) Then run in point blank, that he will be on bullet path between you and your merc/slave.
6) Start shoot your merc/slave like crazy.
7) People will see that and start shoot that guy, usually 1-3 people dying, in armors and with weapon.
2.
1) Do the same as above till #3.
- - -
4) Run in point blank to some guy from respawn with only 10-13 HP and start shoot like crazy, you'll often see "Oops! <Your poor victim> was hit instead of merc. You may kill him or atleast bring to negative HP, also some idiot will try to "help" you and die with victim hahaha!
It'll make your gameplay much funnier and you'll see alot dead innocent people in NCR, as it should be!
Edit:
1) Unfortunately later they all will start hate you and will chase you with 10mm smg.
2) Also bullets ending too fast.
3) And don't load you fun with full clip if it has alot ammo there (tommy gun, AR) because of misses, there's high chance that miss can be critical and you lose all ammo.