I'll often pace around for the same result. Of course I GM 2 of the three games I'm in, so it's not disruptive in those.
Top of my annoyance list: making a drug deal on your cell phone during the game...
Other
favorites that I've been hit with over the years:
- Bringing your drugs or drug paraphenilia to the game.
- Having your supplier show up when we go out so you can make a buy off him.
- Staring at the female players. Putting a chair in front of them and staring without moving for hours...
- Showing up high.
- Rubbing up against the female players and 'feeling' them with your entire body until the men in the room form a body shield around them to keep you away.
- Sending emails to the entire group that quote random lines of poetry, random posts by other members to online forums from years back, and strange cryptic threats if you don't get your way. Note that all the above elements are sent in fragments that often cut off in mid word, so the group doesn't even know it's a threat until they all put their emails together and find the full word or full sentence...
- Challenging the DM online in public forums where you attack all the DMs rulings, claim they have no right to make rulings about the game or even the rules of the house, and using racial slurs or political and religious attacks when doing so.
- Shooting everything with your crossbow before you know what it is.
- Peering at the map and saying you're going to the hidden castle / ruins / dungeon / etc - before your character knows it's there.
- Insisting on having all the abilities and powers of every other PC in the game.
- Picking verbal fights out of character - ending with physical threats
- In character gang-raping all the female PCs.
- In character gang-raping all the PCs of female players.
- Insisting on bringing rape into the game in one form or another.