It's relatively easy to disable a payment method (e.g. credit card or paypal) in all banners using https://meta.wikimedia.org/wiki/MediaWiki:FR2013/Resources/PaymentOutages.js. However during the 6C campaign we experienced problems specifically with recurring paypal. Disabling only this required manually editing each banner, and was made even more complicated by having to disable in-banner monthly convert for it.

We should try to make this simpler in case of future problems.