Comment too much on Dan's articles, not with hate speech or political bullshit or adverts or anything else against the ToS, but just with differing opinions, and he'll block you.
Which, because PB's CMS seems to be pretty crappy and doesn't actually distinguish between the editorial staff and the normal users, actually prevents the blockee from commenting on any of the blocker's feature articles, not just blocking them from conversing directly with the blocker.