[namelessoracle]

Its a known tactic in competitive online games where you can see your opponents IP address to try to "boot them" via DDOS their local IP so they go down or have lessened performance and you win the match. Also harass or shake down kids they think have money. Fortunately the vast majority of people have dynamic IPs, and could likely get a non effected one by just unplugging their router and letting it get a clean IP.

Because of this, a lot of games companies will try to mask the actual IP of the other users now, and Steam has tooling for games they support for devs on their platform.