It Would Be More Effective If They Used the Right Word

Driving home tonight I saw yet another vehicle with this bumpersticker on it:

I just did a little checking. You can buy a variation of that sticker from numerous vendors.

They all have the same mistake, though. Every single one I found.

It would be just a little more effective if they used the possessive form of it - "its," rather than the contraction "it's" - as in, "it is" or "it has."

Now, just who is it again that's the idiot?