Why Taylor Swift Posted a Bikini Photo

— -- Remember last month when Taylor Swift surprised everyone by posting a photo of herself wearing a bikini that exposed her belly button?

It turns out she didn't do it to shock the world. She did it to stop the paparazzi from making thousands of dollars off of her.

Appearing on BBC Radio 1's Breakfast Show with host Nick Grimshaw and Ed Sheeran, Swift explained that she and the members of the group HAIM were on vacation in Hawaii and were having a great time, in part because they weren't being stalked by photographers.

But at one point, Swift revealed, she and the girls went whale-watching and realized that there was another boat out in the middle of the ocean with them ... and there was paparazzi on it.

"My security gets out the binoculars and sees that they have a huge long lens camera," she said. "At which point, we go back to the beach and realize, 'OK, so they got pictures of us in our bikinis.' I don't want them to make, like, $100,000...for a bikini shot. And so we're like, 'Get up on the bow of the boat: we're taking better bikini shots so that they don't make as much money on theirs."

She says later that she found out that paparazzi had actually been stalking them the entire time, and their lenses were so powerful that they could capture them from miles away.

"I've never seen such stealth mode paparazzi, like, long-lensing it up, three miles away," she noted.