Yes, when done in good faith. This is customary like trying tastes of beer from a bartender when selecting the beer one wants a pint of. Draining electricity with an antenna is neither customary nor done in good faith…

Your analogy would be better if it were asking if it’s okay to walk through the store daily and take a couple grapes to add to my fruit basket at home.

You mean it is customary to place your mouth on beer tap and take a sip? Strange customs over there...