Buying questionable bike light

 
This is kinda in response to the guy who had his bike lights taken.I have also had 2 lights taken off my bike.Both during the day,I was foolishly and thought they would be fine,as I was not going to be very long.I take full blame for being stupid.At several of the big events in the summer,the taste,loola,4th July,North coast fest and once when waiting for a light.I have had several people approach me with bike lights wanting $10 for them.I am 99.999999% sure they are stolened lights.Do I buy them or not?I have lights but could give them to my other friends or donate them to Working Bikes or West Town.