I've been testing DuckDuckGo's App Tracking Protection (beta) for the past 24 hours.
Here's a small comparison between #Twitter #Mastodon and #Bluesky (with about equal usage/screen time).
Bluesky is by far the worst with almost 2200 tracking attempts.

Edit: I'd just like to make clear that this beta can be used by anyone with the regular DuckDuckGo browser app (on Android, don't know about iOS).

Twitter gets to second place with 355 tracking attempts, which I expected to be higher.
And Mastodon - using the Tusky app for Android - is the absolute winner with 0 tracking attempts, which I can't show because there was nothing to track.
"Fun" fact: by the end of the day Bluesky had over 5000 tracking attempts.
@Rii_cck
Oh whow dat is serieus.
@Rii_cck X probably would have been higher before losing so many advertisers. Lol. Great comparisons though. Further evidence that the fediverse is the way to go.
@Rii_cck Rick, do you have lists of the the URLs the trackers were pinging? It would be interesting to know. I understand there are some website analytics tools that get incorporated into source, and could resemble ad trackers.
@Rii_cck Whoa... Imagine Threads, then... 😬

@Rii_cck

I wondered what the situation was with Mastodon. Probably zero trackers?)

@Rii_cck Jackboot Jack is not your friend, he’s just better at keeping his mask on than Space Karen.
@Rii_cck Thanks for the edit, I have enabled it too now. Curious to see how many trackers would have come through.