Google and some of the biggest advertising networks like he Media Innovation Group, Gannet’s PointRoll, and Vibrant were accused by the Wall Street Journal of exploiting the Apple's Safari security settings in order to allow a site set tracking cookies. The trick was used in the Google’s DoubleClick adverts that were found on major websites, including AOL.com, Match.com, TMZ.com and YellowPages.com.
Safari for Mac and PC, as well as Safari in-built into iOS devices, are thought to be affected. The browser was subject to tests by the Journal which show that Google used code in its advertisements to bypass Safari’s security, which by default blocks such tracking activity.
The aim of the code was to allow users who had signed into Google+ in Safari to access the ‘+1' button within ads, provided by Google’s DoubleClick network.
Safari’s security would normally prevent ads from dropping a tracking cookie in such a case because it blocks cookies coming from advertising networks. But the code Google is accused of using ’tricked’ the browser into thinking the code was submitting a web form to Google; form cookies are not blocked, as it allows the browser to see whether the form was in fact sent.