That second half seems like a lot of work for minimal gain. Beyond the hypotheticals outlined in the post, and perhaps not accounting for where someone who is already a privacy advocate would likely be taking measures to obfuscate their own traffic, who is actually going to try to monetize such data? And the data simply being “X tried looking up Y”? Am I missing something more profound?
Discussion
The privacy gain is a nice side effect of using probabilistic filters but not main benefit as far as I'm concerned. the benefit to using them is allowing clients to quickly check if a server says its hosting blobs.
The existing HEAD /