Valve confirms credit card companies pressured it to delist certain adult games

Why do payment processors do stuff like this? Is there some regulation that requires them to? I get that they don't want to process fraudulent transactions, but I'd think the response to a higher percentage of fraud from some industry would be to charge them more. It doesn't make sense to me why they would be concerned about the content of games, as long as everything is legal and the parties concerned aren't subject to sanctions.

Some of these games seem completely abhorrent, and probably illegal in more restrictive jurisdictions, but not the United States. And I've not seen any suggestion they're funding terrorism or something. So I'm perplexed.

Another factor is that credit providers (i.e. banks) are increasingly using customer transaction data to assess customer behaviour as part of its risk scoring.

If a customer is regularly purchasing adult material that would be definitely be a red flag.

A red flag of what?

Defaulting on their credit card bill. Or the account ends up having been started by an identity fraudster. Which also ends in default.