The Struggle Against Imperialism and for Workers' Power in Iran is a $3.50 pamphlet by Keith Jones of the Socialist Equality Party of Canada; published by Mehring Books and distributed by the World Socialist Web Site.
Paypal has refused to process transactions for the sale of this pamphlet, and refuses to say why, "except via a subpoena." The block was reviewed by a Paypal supervisor, who said ""It is something where we can't change it. You are not going to be allowed to process [sales of the book], based on compliance reasons."
It's possible that Paypal is simply blocking anything with the word "Iran" in its description in order to ensure compliance with the economic sanctions regime against Iran. However, a cursory examination (which you'd hope the supervisor would have engaged in) would reveal that a pamphlet by a Canadian about "the history of Iran and the international Marxist movement throughout the 20th Century" that "addresses basic questions of socialist perspective for the working class in a country that has been a target of US imperialist aggression for almost four decades" has no nexus with these sanctions.
In April 2013, PayPal briefly blocked the sale of a photo book produced by an Italian communications firm, Fabrica, containing a collection of images taken by photographers in Tehran from inside their homes. PayPal staff stated at the time that the book had been automatically banned because its title contained the blacklisted word "Iranian."
In that case the ban was removed within two days. PayPal issued a public apology via technology blog Gigaom, claiming that the ban was a mistake and noting that PayPal's adherence to US economic sanctions was "never intended to apply to books or written materials and we have worked to ensure that books are not impacted by our compliance with this policy."
In 2015, PayPal also placed a financial blockade on Justice for Iran, an organization that exposes human rights abuses inside Iran.
PayPal blocks sale of WSWS pamphlet [Will Morrow/World Socialist Web Site]