Do Wiis scratch discs?

[novasonic]

So, as I was buying Fragile Dreams at EB two days ago, the guy tried to sell me up on the disc scratch warrenty like they always do. But this guy made a huge stink about how I was making a mistake not getting it. Telling me that Wiis are netorious for scratching the discs as they suck them up. I pretty much called his bluff, and told him that they don't. He was being a big dick about it too. But it got me wondering.. do they? It's never happened to be before, and I've never heard or read about this happening to anyone.