Comment by saddlerustle

PayPal compliance is a very different problem to social media moderation. Financial regulations require any transaction that is "suspicious" in any way of having links to terrorism financing or money laundering be reviewed, and there are large and personal penalties for not doing so. And a review is expected to be more like auditing your customers entire financial history than just asking what they meant by a word, so for a consumer service like PayPal the only real option is to block the transaction. In that climate there's no good reason not to massively over-filter, the risks of a false negative are way too high.