I was talking to a US business owner friend of mine about accepting BTC. (They have an international user base and have to deal with a lot of fraudulent orders.) He likes the idea of no chargebacks, of course, but he's afraid to accept BTC because "what if they pay with stolen BTC and later law enforcement comes along later and wants to seize it?"

What would you recommend I say to allay this fear?

Is it even a legitimate fear? Of course they could just sell all the BTC that comes in, but what if they want to hodl some? Do they have to coinjoin everything that comes in?