Google's fault for their confusing branding. OP's headline is one of the two perfectly understandable parsings: (YouTube (TV Clients)) vs ((YouTube TV) Clients)

You did not read it correctly. Author stated that people are modifying and redistributing their code in an unauthorized manner.

Did those people sign a legally-binding end-user license agreement?

Because what I see is essentially "they're storing stolen property" but the burden of proof is on the author to prove it was, indeed, stolen.

I imagine the bar for that is pretty high otherwise anyone could weaponize DMCA to target their competitors' repositories.

You seem to be thinking about "adblocker running in browser", since you brought up EULAs.

That's not what OP alleges - they are saying people are redistributing modified versions of OP's copyrighted code. DMCA is an appropriate measure in such a situation, but it's unclear why OP's DMCA takedown was rejected by GitHub. Without more detail, it's hard to comment further

one would think, if it is still up there, OP might point us at it so we can see for ourselves, right now it's "trust me"

People are absolutely abusing the DMCA process.

https://reclaimthenet.org/kiwi-farms-dmca-subpoena-anonymous...

USPS still sells denominated stamps from $0.01 to $10.00, in addition to "First Class Forever" stamps - see near the bottom of the filters sidebar on https://store.usps.com/store/stamps

There's also other types of forever stamps, such as the domestic Postcard and Global Forever stamp!

These are problematic as well - they don’t have a way to tally the stamps, they just look for the marker and process it. A postal employee at the delivery point may flag it.

Also if you mail stuff this way you’ll have mail inspected for bombs or anthrax.

Fn+Tab is the backlight toggle on my V5 Max (and it's specifically called out in the user manual https://www.keychron.com/pages/keychron-v5-max-user-manual)