Does anybody with a STRONG BACKGROUND IN WEBSITE PRIVACY have time to vet this research? Are TikTok and Meta pixels REALLY doing the things claimed? I'm concerned it may be overstating things in an attempt to sell its tag monitoring tools.

https://jscrambler.com/blog/beyond-analytics-tiktok-meta-ad-pixels

The Collection of Commercial Intelligence: TikTok & Meta Ad Pixels

Jscrambler analyzed the TikTok and Meta ad pixels used on websites and found that their default behavior requires immediate attention.

Jscrambler
@dangoodin it looks credible, given a 5 minute read and a few decades pottering around in the software industry. The behaviour (scraping data before consent) fits perfectly with other reported bad habits, e.g. https://localmess.github.io/
They probably justify it as, “Well, it’s called metadata, so it’s obviously ours.”
Covert Web-to-App Tracking via Localhost on Android