Does demanding to see called poker hands at showdown give unfair advantage to some poker players?

Secrets in the muck?

All poker players have been annoyed at one time or another when other players demand to see their hands after a call when they are thrown into the muck. The accepted explanation for this is that it helps to identify collusion at the table.

But does it? And does it somehow favor certain players over others?

Here's a pretty good article on the subject.