Why is so "Intrusive" (on first sight) the Terms of Github Community?

When I tried to join this community, it showed me:

“Act on your behalf” -without any further hint or explanation. I have seen on different communities “Post on behalf of me, do this or that…” but I have never seen any more intrusive claim than this. What does “Act on behalf of me” means with my account? It can be rephrased “everything in my account”.


There’s a thread about this over here > Why does this forum need permission to act on my behalf?