How did the Goblin get phone number to Martys mother and GF?

Watching good ol clips of Goblinslaying by MBM, and I have been absolutely puzzled - how TF did the Goblin get ahold of phone number to MBMs mother and his GF?

Was Seren also active in the trolling, or what? And even if so, I doubt that his mom was. And I highly doubt that the boy from the attic was able to find this all out by himself.

I love (loved) Marty, but boy - if the guy you are trolling on the internet has phone mumber to you mother, that is not good.