Board Thread:Support Requests - Community Management/@comment-35264290-20180519080330/@comment-1038387-20180519182606

Yup, as a Global Discussion Moderator, I can only do anything on wikis I'm assigned to. And even then, on Discussions. And even then, I do not outrank a local admin. Even if I browse on another wiki's Discussions and see spam, I'm not actually allowed to delete it. It's a community support role, with clearly limited powers. I'm not even sure if I could unblock you - I've never checked whether I actually have that power - but if I did, the local admins could just reinstate the block, ask me what the heck I was doing, and then report me to staff for seriously overstepping my authority. That's, if I actually wanted to unblock you.

For the rest, I refer you to what Sugiotastic said.