This may not be true. I blocked someone, and was still able to see their posts in publications. I don't know if there was a temporary glitch, or if that's by design, but it's something to keep in mind.

It may be that they cannot see mine, and that's really the hope, when blocking someone - that they don't see your material (especially in the case of willful copyright violators) and that they cannot interact with you (in the case of inappropriate or harassing behavior).