Blocking users does not block their updates when you track their keywords

When I track some interests, I start getting notifications from the same people who either use that keyword to spam me, or can't shut up about their own opinions about that keyword. I think it is an automated script that keeps putting out updates with the keyword I want to track!

I have tried blocking just those users, but because of the keyword, they keep coming through. Can the block function override the track request? Or am I simply doing it wrong?