^ all of this is completely correct. I'll also add that many virtual credit cards that have "limits" or that let you "turn them off" work by not allowing transa

^ all of this is completely correct. I'll also add that many virtual credit cards that have "limits" or that let you "turn them off" work by not allowing transactions to auth, but merchants can almost always force an authorization that cannot be blocked. If you don't want to pay someone for a service you signed up for, you really do have to cancel your agreement with them, you can't just stop paying them. I'm very excited about the new click-to-cancel rule for this reason — hopefully doing the "right" thing will be really easy and actually work.