It's about paypal acting on behalf of and as an agent of the US government.
If it were just paypal they absolutely wouldn't care about the subject so much as to match random characters in descriptions, wouldn't give people zero recourse, etc.
The US government may not pass laws to achieve an unconstitutional end, even if it's achieved through third parties. If that is the effect of the law, then the law is invalid no mater how many times the "I was just following orders" trope is repeated.
If it were just paypal they absolutely wouldn't care about the subject so much as to match random characters in descriptions, wouldn't give people zero recourse, etc.