sure, among the more experienced webmasters. never come across zango (i am on linux) nor do i use it on sites.
i check for agent, so spider have its own agent, if it's not in the list of supported browsers by zango, i don't show zango content
but your site is still at risk to face penalties for adware... google has not only it´s official spiders
you mean like some antivirus will say something bad whenever user will go to your site? what do you against that?