After hearing all the punitive and reactionary measures advocated here, I feel that I must reiterate that the players haven't done anything wrong. Gear taken from enemies is a staple of practically all RPGs and EotE (and FFG SW in general) is no exception.
"Gear" meaning "only the best". I was reading the D&D5 PH last night (prepping for a one-shot) and under equipment there's a specific paragraph about gear (AFB paraphrase): gear that you sell only nets you 25% of the listed price, and gear taken from monsters is rarely worth anything at all. Those economic assumptions combined with encumbrance is bound to limit looting.