It is worth noting blocked by uBlock Origin != tracker, even though that likely is the case here. You can use uBlock Origin's logger to see what is blocked.

Network requests can be many things, not just ads. In fact, most of blocked requests should be for tracking since websites usually fire tracking request periodically. Even even you just leave the tab open in the background.

reddit.com/r/uBlockOrigin/comm…

Based on my testing, there are two domains blocked on Bluesky; events.bsky.app and sentry.io. Both are blocked by EasyPrivacy, which is maintained by the EasyList project and is enabled by default in uBlock Origin. Some members of the EasyList team also are part of the uBlock Origin team, and it is a respected project in the content filtering community.

events.bsky.app is first party telemetry. It collects standard telemetry information; referrer, session ID, platform (web), IP geolocation down to the state (for US), current and previous screen (i.e. the home page), and app language. Someone did report the excessive requests as a bug, but Bluesky never responded to or addressed that report, and it is possible they are not aware of it. My guess here is that since it is blocked by uBo, the code assumes the request failed and retries it, forever. I haven't bothered confirming this, but I have heard of this happening on other sites. These retries are fairly infrequent, but if you keep the tab open long enough, they build up; given the 452 blocked requests make up 47% of the requests from this tab, I would assume this tab has been open for a long time and has accumulated many requests. In any case, the large number here is greatly inflated. If I am right, the large number is an indication of poor programming, but not a privacy invasion. If someone wasn't using uBlock Origin or equivalent software, the number of requests to this domain would probably be lower.

sentry.io is "application monitoring software". The decision to block Sentry as a tracker is not uncontroversial. I support it being blocked, but there isn't any sinister going on here. Bluesky is using Sentry to know when their users encounter errors. Whether you want them to have that data is a personal choice; I personally agree with EasyList's decision to block it, but that's just my opinion.

Also, neither of these domains relate to ads (you weren't claiming that, to be clear, but I just wanted to clarify in case someone was confused), and only one of them is a third-party "tracker" (air quotes because Sentry is controversial).

Without seeing the actual network requests uBo is blocking on your device, I can't confirm you are seeing the same results I see in my tests. I have not been able to reproduce the high volume of blocked requests, though I do see requests sent when I scroll (which makes sense as it is telemetry).

TLDR; the number of blocked requests here is very deceptive. There are two main trackers; a first-party analytics service and an error tracking service. If you consider these invasive, fine. But that determination should be based on what information they are collecting, rather than the fact there are many blocked requests from them.

And, no, I'm not a Bluesky stan. Bluesky has plenty of problems, but I want to make sure people understand what uBlock Origin is showing here and what it means.

Source: I have been using and contributing to uBlock Origin since 2021, and maintain several filterlists.