I've been dabbling in This Thing of Ours for a long time. Yes, BBFS happens. I don't do FS in sessions at all (those that know me know that BBBJ is my thing) but it's something that's on the table more often than we care to admit. Typically with long-time regulars, who have established that they're not idiots. Sometimes indiscriminately.

Each person, hobbyist or provider, has to decide what risk profile they're comfortable with. I don't think doing BBFS is wise, unless you know someone EXTREMELY well. And that rarely applies to hobbyists and providers.