Have you seen/heard of this before...

[DDC67]

Last month I was sitting at a 1/2 NL table when the poker room manager came over and announced that a "fish" was coming into the game. I appreciated the tip and sat back and watched this guy for a few hands before deciding if the information was accurate. I was wondering if this is appropriate for the poker room manager to do/say, even if the player asked for this to be done. Any comments??