McVeigh bombed the Alfred P. Murrah building in Oklahoma City in 1995, killing 168 people, including 19 children, and injuring hundreds more. He is scheduled to die by lethal injection on Wednesday.

This genre of merchandise is "soon to be banned from eBay," some vendors have noted as an inducement to buyers.

On May 17, the site will ban all sales of novelties and past belongings of notorious murderers, including letters, T-shirts and artwork. It will no longer allow sales of items linked to hate groups, Nazis or the Ku Klux Klan.

EBay spokesman Kevin Pursglove said it was "a pretty tough decision to make for a site that allows people to trade practically anything." But the fear was that the items people were selling glorified killers and revived horrible memories for the families of murder victims, he said.

Vendors had used eBay to sell a killer's hair clippings, crime-scene photographs of two teens killed in Tennessee and a pen from "Night Stalker" Randy Ramirez, he said.

After the ban takes effect, eBay officials will watch 24 hours a day for attempts to market prohibited materials, Pursglove said. Site monitors are already on notice to watch out for one anticipated item: pirated video of McVeigh's execution.