Mackenzie PhillipsLate last year, Mackenzie Phillips appeared on the OWN network's "Extreme Clutter" with Peter Walsh. Yep, she has a little hoarding problem. She says her "hidden clutter", which is mostly family memorabilia, is her way of hanging on to the past. With Peter's help, she's ready to let go of the things that have negative power and keep the things that have meaning for her future. Good for her for tackling her hoard.