In Privacy Settings, what does checking "Do not let this member follow me or my activities." do ?
If a member's profile does not show "activity" does that mean that he/she has you on ignore ?
The "activities" part of that means the member can't view your activity list, but I'm not entirely convinced that that necessarily means you've been blocked with that option. I suppose the list could have been deleted, or maybe there's no activity to see. I seem to remember an option to hide your own activity list, but maybe it was a dream...
If you aren't sure if your post will violate the ToS, just don't post it. Err on the side of caution and this forum will live a long and happy life.