The usual HF grabs have been these dudes that broadcast for long hours, or frequently everyday, on the same FREQ and location. Usually around Christmas and NYD you hear about that happening, but you still can be pretty safe to do a gorilla warfare style of broadcasting portable and mobile. Also, take advantage of upper HF propagation, like this December's 11M Sporadic E, where the TX has a small local footprint, but may skip over several federal monitoring stations. With Medium Wave, you'll still have a dent sized local footprint and about every monitoring station could RX and triangulate. I base this upon past experiences, but I don't see these scenarios changing too soon.