So basically if I'm careful I can get away with ordering someone a butt plug with cash, and if I'm careful I can get away with ordering someone a butt plug with bitcoins... can you see why I fail to see this as a real problem or at least a bitcoin specific one?
The question I raised was, is it a problem (if a minor one) for a merchant. Someone who is going to be an asshole can be one without any specific tools ( though a butt plug may make them a bigger asshole
In either case you are unlikely to be able to find the culprit. So a particularly annoyed target may take out their irritation on who they can find.
In the case of a debit card you have the merchant who shipped the product, the card issuer and the store that sold the card all sharing the irritation of the target.
In the case of bitcoin there is just the merchant to put up with all the complaints.
Edit: Also since it is a bit easier to do with bitcoins than a debit card, it could be more common with bitcoin accepting merchants.