[lucb1e]

> If you were to only see a hash of my username, you could track me, but you couldn't identify me with it.

Pseudonymous is the word for that sort of "tracking". Tracking just means being tracked, no matter if they use the real name or a hash of it or fingerprinting/metadata like IP + user agent string + installed fonts.

[staticassertion]

Yeah, that's my point. Anonymity to me implies that you can not determine my true identity. That property still holds here. What doesn't hold is that you can not determine that I am the same person in multiple locations - a very significant issue, but a much less serious one.

[strbean]

One feeds into the other strongly, though. The odds of an adversary de-anonymizing you go up the more activity the adversary can see. Also, we should look at your anonymity on a per-site/session basis, and if de-anonymization on one site breaks your anonymity on other sites, that is bad.

[staticassertion]

I fully agree that it is bad and a legitimate issue. As I said, "a very significant issue".