Looks like some big changes are coming for Pixiv’s Terms next month that includes Fanbox.https://www.pixiv.net/info.php?id=8788
“Currently, many transactions are taking place on BOOTH, pixivFANBOX and pixiv Request function.
Among them, we have confirmed that some transactions have violated Article 14, Item 26 of our Terms of Service Prohibited Activities, which stipulates "the act of using this service to exhibit, sell, purchase, register, or otherwise conduct transactions for the following products.
In addition, the terms and conditions of international card brands, etc. also prohibit transactions of content or products that include the following
-Child pornography or child abuse
-Rape (sexual acts without consent)
-Illegal mutilation of the person or body
-Acts that are offensive to public order and morals”