Bukkit

I have a high traffic server and some of the time players are killed while in there own region, which on my server is against the rules. I would like to know how to set pvp off in all regions. I know by default pvp is allowed, how can I change this instead of manually going into the 1300+ regions and turning off pvp?

As far as adding the flag to future regions simply add this into the "Flags" Section of the config.yml:

Flags:
- pvp deny

As far as adding it retroactively you wouldn't be able to do it with a PS Command, and as far as I know WorldGuard doesn't have this option. The current plan for PS is to add the ability, but I currently have no time frame on when this will be added.

For now you might want to check on WorldGuard's Page to see if they've added any commands to do this, or if you are using Essentials or other plugin you could turn it off globally for the whole server.