You can't tell the Wii has been opened because there's no security sticker over a screw. If Nintendo would have done that, I wouldn't have modded my Wii. It's their own fault for making the Wii openable without it being noticed by a store employee.
That's the stupidest thing that I've ever heard. It's not their fault for making their system "hackable." Just because they didn't put a sticker over a screw doesn't mean that you're alleviated from all responsibly from modifying your system and downloading/burning games.
If they had put a "security sticker" over a screw, then the mod chips would be sold with replacement security stickers. And then you'd go "Well what the hell Nintendo. It's your own fault I'm modding your system. This security sticker is so easy to get around. You should have welded your case shut." And so on.
I mean, I'm gonna mod my Wii too really soon. It's not like I'm really against this process or anything. But just don't think that because people have figured out how to bypass the myriad of Wii security features that were put in place it's somehow Nintendo's own fault.