When I shared a draft post with some friends, a lot of them had an ah-ha moment, so I was hoping for the same from others. I was trying to illustrate 2 privacy concerns around the graph Bitcoin exposes: (1) accidental associations and (2) exposing the people you transact with to each other.
In the blog's hypothetical, you're not receiving money from some asshole because you're collecting Klan dues from him. Rather, you performed some public transaction with a stranger. For example, maybe you sold him some tickets. An external observer of the graph who knows he's a dangerous character may start applying high odds that you, too, are a dangerous character, since they don't know why he sent you money. This would suck. And, second, this character who sent you money may also be learning things about you. Since you sold tickets to a local show and mailed them to him, (1) he's likely to live near you, and (2) he knows your return address. You really don't want him seeing that you're sending money to causes he opposes. If so, he might show up at your door.
The goal was to clear up this misconception that a private cryptocurrency is there to protect criminals. This is especially important if you'd like to post a static address on a profile.