When does a privacy enhancement become a privacy distribution mechanism? OPS was a distributed content tagging system with the idea that various organizations would rate web content, and browsers would subscribe to the user’s desired system. I wrote this article about it in 1997, but it’s become relevant again as we discuss how to do distributed content-moderation on federated systems like Mastodon. Bluesky has proposed a similar system as well. What’s interesting is that the threat and privacy models have changed considerably since then.