Hah. Literally an hour ago I fat-fingered the “Sign up to Amazon Music!” button in the Amazon Music App on my phone whilst putting the phone in my pocket.
To be fair to Amazon though, they do let you cancel the subscription online with no bullshit & you still get to keep the 90 day free trial -- presumably they hope you’ll like the service enough to decide to pay for it anyway.
(The worst example I know of this “single button press sign-up” pattern was Nassim Taleb accidentally signing up to pay for a software upgrade to his Tesla in the Tesla App that cost $1000s & having no way to undo it except shouting loudly at Tesla / Elon Musk on Twitter.)