That's the question dogging the bushy-browed Muppet after his face mysteriously appeared on posters of Osama bin Laden hoisted by anti-American demonstrators in Bangladesh.
The strange image was captured in news photos and soon began making the rounds on the Internet, amusing some but angering Bert's owners at the Sesame Workshop in New York.
The roots of Bert's Bin Laden connection date to 1996, when Filipino art student Dino Ignacio, now 27, launched a tongue-in-cheek "Bert is Evil" Web site ( http://www.fractalcow.com/bert/bert.htm ).
The site shows doctored photos of the fuzzy children's icon with everyone from Adolf Hitler and the Ku Klux Klan to talk-show host Jerry Springer and former basketball player Dennis Rodman.
Ignacio's creation spawned numerous imitators, including a site that added Bert to a photo of Bin Laden. From there, the Bert-and-Bin portrait was downloaded by a Bangladesh print shop and incorporated into a collage-style poster with a printing of 2,000, according to the Associated Press.
"We did not give the pictures a second look or realize what they signified until you pointed it out to us," said Mostafa Kamal, the shop's production manager.
But plenty of others did notice. When photos of the Bangladesh protest began circulating, Reuters fielded so many calls that one picture editor said she jokingly answered the phone, "Bert and Ernie hotline."
And Bert's corporate masters at the Sesame Workshop were not amused.
On Wednesday, they issued a statement decrying the Muppet's unauthorized cameo: "We're outraged that our characters would be used in this unfortunate and distasteful manner," a spokesman said. "This is not at all humorous. The people responsible for this should be ashamed.... We are exploring all legal options to stop this abuse and any similar abuses in the future."
Ignacio likewise disavowed Bert's latest incarnation. "I had nothing to do with this," said Ignacio, who is now a student in San Francisco. "That image was never on my site."
But the Bert-is-evil theme has been adopted by others. Since Sept. 11, Ignacio has received a stream of doctored Bert photos via e-mail, including several showing Bert hiding in the rubble of the World Trade Center or running from the scene wearing a backpack.
"I've been trying to stay out of it because this is too touchy a subject," Ignacio said. "I haven't even updated my 'Bert is Evil' site since 1998. But sometimes when you create something and you want to move on, it creeps back and bites you."