

I have had a similar experience. Most sites with Anubis take only a few seconds to go through, but I ran into I think it was some small blog where it took at least 5 minutes. Like someone mentioned, it may have been how they set it up with number of hashes required. The site that took forever for me seemed to have some exorbitant number like 5k or 50k (I don’t recall exactly).
I’m inclined to think that your IP provides powerful cross-reference potential. Imagine someone either buys the data off of all data brokers out there or a law enforcement agency obtains similar kind of data through warrants, etc. They can cross-reference IPs and time-stamps and determine, that you, Joe Blow, age 35, who works at X, volunteers at Y, and lives at 123 main street, browse for some kind of very embarrassing porn every night. It’s a drastic example to illustrate the idea, but I don’t think it’s far-fetched.
This could be taken further by imagining a wider net: say, a large portion of people who have donated to this political candidate or who work for this company browse for that same embarrassing porn every night.
I’m thinking birds-eye view of potential privacy violations here.