It is standard proceedure at most
poker sites to show any mucked hand that calls the river if it is a losing hand. Perhaps a way of giving the players a way to detect collision if the take the time to actually look at hand histories.
When I found out about this playing at Ultimate Bet I was pretty darn happy to learn that little tidbit. I use it to my advantage to get a great deal of incite as to what kind of hand my opponents will call the river with.
One might think this could work against you. However, I look at it this way. One, many of my opponents at the low levels I am playing at don't even know what the hand history button is worth. And, the ones that do are not going to get much information off of me. Why, because a tight-aggressive or even semi-tight semi-aggressive player like myself is not involved in many hands. So, building up a read is a lot harder than with loose aggressive or calling stations. I have much more to gain by seeing mucked river hands of others then others have to gain from seeing mine.