The Montreal Canadiens traded away several depth pieces leading up to the trade deadline. They moved out Marco Scandella a few days before the deadline, then traded Ilya Kovalchuk the night before. On deadline day they moved out Nate Thompson, Matthew Peca and Nick Cousins.
This brought in several draft picks to the organization and was the right approach as all of those players are going to be free agents in the summer and would have left for nothing at that time. With the Habs too far back in the playoff race, they may as well acquire future draft picks for expiring contracts.