Well, I would certainly consider anti-Flarm countermeasures to be unsportsmanlike in the extreme. However, unless Flarm use is mandated in that contest, then supressing one's Flarm signal or turning it off altogether would not be actionable under the rules. And, as Ron said, how would we know with certainty that someone was screwing around with their Flarm signal?

I know we gotta have rules, and situations arise where mandates are justified, but the idea of more rules and mandates generally sets my teeth on edge..