I've heard of yarn stash problems, but...
"WOODSTOCK -- A grandmotherly-looking woman is one of the two people accused of stealing thousands of dollars in yarn from stores in metro Atlanta.Skeins and skeins of yarn has become the target of thieves in Woodstock.“She looked like your typical grandmother,” says Debi Light."
I've seen complaints on knitting lists about yarn store owners following people around the store. If one woman can steal $13K worth of yarn from one store (over time), I don't wonder!
Most knitters, however, pay for their stash. I am trying not to become one of those SABLE (Stash Acquired Beyond Lifetime Expectations) knitters -- I have a portion of my sewing room closet allocated to yarn, and am on a yarn diet trying to use up some of what I have before buying more. Ditto fabric -- I have entirely too much fabric, and am trying to use up or sell some of it.
There have been studies on hoarding activities. People who acquire large numbers of, say, cats -- to the point where their own lives, and the lives of the cats, becomes unsanitary -- are suffering from a specific kind of mental illness. I suppose that hoarding fiber or books or yarn is a lot less harmful overall than hoarding cats, but I think the woman who stole $13,000 worth of yarn really needs help.