"monetary forfeiture" is a fancy phrase for "fine"
When I said they did a lot, I didn't necessarily mean they often seize radio equipment. A 5-digit fine is usually enough to dissuade anyone, and most interference violations aren't with equipment used entirely for jamming, but legitimate equipment used on the wrong frequency, with excess power, or otherwise in a prohibited way.
I'm also unclear as to what differentiates a fine from a monetary forfeiture.