So why do they allow banner ads to look like download buttons anyway? I mean, there's no real reason you should be able to pass an ad off as a download link, so

So why do they allow banner ads to look like download buttons anyway? I mean, there's no real reason you should be able to pass an ad off as a download link, so wouldn't the obvious answer just be to ban ads that look like that? Heck, you could probably even automate that process with Google's technology. If OCR technology can identify captchas, it can probably identify button shapes in images or text that looks like program information.