In this example collected from the Snopes inbox in August 2009:
Someone sent me this link about sears posting a grill to cook babies. Is this true?
Origins: Until midday, on 20 August 2009, the website of home retailer Sears displayed a listing offering a Kenmore brand natural gas grill listed under the category of "Human Cooking > Grills to Cook Babies and More > Body Part Roaster."
Sears eliminated the entry after the unusual listing was pointed out to them and stated that "someone visiting" its site had altered the original:
We discovered earlier today that someone visiting our site had defaced a limited number of product pages. It's important for our customers to know that we have no reason to believe that any of our customer or financial data were compromised. We've already taken steps to prevent this from happening again. We sincerely apologize to any customers who may have seen this on our site.
As explained on Reddit, the unusual listing was the result of some technical flaws in Sears' website that displayed and cached user-submitted data, not an actual "defacement" of an existing page.