Gartner Marketing Unsubscribe (dark pattern)

Has anyone else had Garnter emails start spamming them? Somehow they got my email address about a week ago and now I get one+ email a day.

Their unsubscribe process is ridiculous (illegal?). First you have to re-enter your email address (it should be included in the unsubscribe link in the email, right?) then you have to _solve a captcha_ just to hit submit on your unsubscribe request. Finally, for me at least, this goes to a "page loading" gif which never actually loads (there may be some ad-blocking stuff interfering with requests or something, I still have to check, but GOD DAMN).

I don't know the rules about unsubscribing from lists you never subscribed to, but they seemingly make it impossible to actually unsubscribe unless you are very determined. Yes, I can redirect to spam pretty easily, but I hate this shit.