I never heard of "increasing reports of [whatever] on the Internet" as being a valid point.
Look, there are lawsuits because people want money. It's quite simple, really.
The Wii is the hot thing this holiday season, and well into next year.
Nintendo is making mucho moola because of the Wii (not to mention the DS, and amazingly, GBAs are still selling).
People think, "oooh, we can sue whoever's hot right now - and at the moment it's clearly Nintendo - and sue them for lots and if they decide to throw money our way to get us to drop it, that settlement will still likely be a lot of money too".
Once some people started getting injuries related to their mishandling of the Wii Remote, they got their reason to sue and the rest falls into place.