Many ads are activated in response to touch events.  Often the ad does this incorrectly resulting in a poor user experience and bad conversion metrics, eg:
 - triggering navigation on touchstart or touchend even after a scroll (mitigated by  issue 582140 )
 - navigating when the user taps to stop a fling (don't get "tap suppression")
 - navigating when the user accidentally taps right after the frame changed positions (could be addressed for click in issue 603193)

To enable a solution to all these issues, ads should be navigating only in response to "click" events (with click-delay elimination as described in https://developers.google.com/web/updates/2013/12/300ms-tap-delay-gone-away?hl=en).  But there's no way for an ad network to enforce this.

Perhaps sandboxed iframes shouldn't, by default, be permitted to trigger a navigation outside of event handlers for (trusted) click events?  Or, worst case, there could be an opt-in option for this.

mkwst WDYT?

See related  issue 611982 .