The Can't Cut List - What is it?

Basically The Can't Cut List is list of the leagues top players. Players are placed on this list to keep low performing teams from dropping top players and affecting the parity of the league.

From Yahoo Fantasy Football Help...

Many of the best players in the game are on this list throughout the season. When a player is on this list, he cannot be waived from a team under any circumstances—even if he's injured.
This list does not affect your ability to swap a player between active and bench, or make a trade involving him. More Here...

So the only way to get a player off your team who is on the can't cut list, is to trade them.