How are you going to ensure that you're legally compliant with "only $X per-year per-person" unless you keep track of who's making every Bitcoin donation to you

How are you going to ensure that you're legally compliant with "only $X per-year per-person" unless you keep track of who's making every Bitcoin donation to you? If you don't do that you could trivially go over the limit by just donating >$X over multiple Bitcoin transactions.