A good rule of thumb: if your page contains a table, you might be better off hiding it from Google and Bing. (WolframAlfa is an easy case because it started out on that premise. So, I am assuming most sensible people blocked it right out of the gate. Google is tricker, but keep working on your scheme, guys and you’ll get there, too!)

One obvious trick that can be used (feel free to comment, BTW): valuable data – e.g., tabular data – can be turned into an image and that image placed in a directory that is off-limits to Google/Bing. I expect this sort of techniques to become standard practice in the coming years as more and more site owners realize they are being dispossessed of their content and reduced to the role of unpaid interns sifting through and “organizing the world’s information” for Google’s profit.