Multiple Browser tabs and Flash

I've noticed this a few times already: If I open up 20 tabs, even in Chrome, (don't mention Firefox cause 20 tabs in Firefox means 4TB RAM and growing) in some cases the processor will just run amok and force the cooler into behaving like a V8. I somehow blame that on Flash things that animate in all those tabs even when they are not enabled/active. Couldn't we have something like "put those on hold" when the tab is not active ? I mean I don't care about them even when they run in the active tab !!? Well, of course I'm talking about ads.