"We've all been there. You fire up a web browser, open loads of tabs for further perusal and suddenly the office is full of noise from an advert proclaiming that in 15 minutes or less you can save on your car insurance – and you've no clue which tab it's in."
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Not me.
Settings > Advanced Settings > Content Settings > Plug-ins > Click-to-Play
Plus AdBlock, Ghostery extensions.
Solved.