[growlers]

Something I see all the time in limit games is when at showdown, the winning player grabs the loser's chips.

Example: Seat 6 bets the river by stacking his chips out, seat 7 calls headsup, seat 6 flips over say second pair, and seat 7 then flips over top pair. Seat 7 then grabs the chips in front of seat 6 while dealer is still mucking the cards and getting ready to push the pot.
Today, at Red Rock, the 8 seat actually grabbed 7 seat's card protector chip and already had it stacked when 7 realizes and says something - seat 8 gave it back but dealer says nothing. This was all before dealer had even pushed the pot.
Now THAT is clearly out of line, but it kinda annoys me when people do this - I feel like it is bad etiquette - but I am wondering if this is standard and I am just a nit for etiquette.
If this is really bad (and I am not just being unreasonable), how do I discourage this without looking like an ass? The dealers at least at RR don't ever say anything.