Why is Toyota hogging my CPU with that Sienna Ad?

My computer seemed a tad sluggish tonight so I brought up task manager to see what was going on. It was running a constant 40% CPU use, and the culprit was Firefox. I had a number of tabs open, so I started closing them 1 by 1. Closing one of the YA! tabs brought it down to 20%. Closing the second took me back to normal.

After mucking around with it for a while, it's definitely that Sienna advert. The stupid Mommy Like/Daddy like ones. They're burning up 20% of the mill, even after the animation is done. WTF?

Same issue in IE. Same issue on an older machine.

Just to verify, I opened firefox, found the advert and deleted it from the DOM. Instant CPU drop.

Anyone else seeing this?

How do you stop this Toyota thing?