@s{quotedtext}
@s{quotedtext}
I think you're exactly right.
FinCEN cares mostly about big-time money laundering and terrorist financing. If I was running a cash-for-bitcoins service in the US and started moving more than a few hundred bitcoins a month through my bank account, then I'd talk to a lawyer. If I was running an exchange, I would have already talked to a lawyer. If I was a US-based miner exchanging more than a few hundred freshly-made bitcoins for cash every month, then I would talk with a lawyer. If you hold other people's bitcoins... then I'd talk with a lawyer (even if you're not a money transmitter, there might be consumer protection or banking laws that might apply).
Otherwise, I wouldn't worry. If I was a miner transferring my bitcoins to an exchange and selling them, then FinCEN won't come after me. FinCEN will get reports from the exchange, and that's what they really care about. The IRS might come after me if I don't report the income, but I think they'd charge me with tax evasion, not being an unlicensed money transmitter.