It's even worse - not only is it stripping links, it's often actually breaking them. The www.glutenfreebay.com example actually should redirect to glutenfreebay.blogspot.com, but instead it's heading to ebay.com.
Understanding which links are affected by this issue and the scope of the problem might be relevant.
In fact, one might go ahead and leap to the conclusion based on our revised understanding (that it does in-fact likely need ebay.com in the url to trigger) that this error is being caused by an unfortunately constructed regular expression or overaggressive pattern match and one might even learn something.
But far be it from me to assume that such a far fetched conjecture has anything to do with it.
!!"eBay.com".match(/ebay.com/i); //true
!!"CrittersByTheBay.com".match(/ebay.com/i); //true
!!"ThePirateBay.com".match(/ebay.com/i); //true