viruses in digital photo frame

Apparently there's a digital photo frame that comes with a virus, and when you plug the frame into your computer, your cpu becomes infected.

My question is, how does that happen? A computer virus isn't like a real virus, where you (or your digital picture frame) can catch it by drinking after someone who has it or getting sneezed on or something. Somebody at the manufacturer/designer had to have done this on purpose. And according to the story, other products have come with viruses too. How does a company do that and not get the pants sued off them? How does an employee do that and not get exposed -- I mean, there's only so many people at the photo frame company who could have possibly done this, it wouldn't be hard to figure out who.

Sorry if this is a D_B

http://tech.yahoo.com/blog/null/66647

 

Insignia's Best Buy brand... interesting...

 

Just bought a Westinghouse... at Best Buy.