rish3 - 8:19 pm on May 6, 2013 (gmt 0) [edited by: tedster at 11:10 am (utc) on May 7, 2013]
I think it could be any of those or even Chrome. All they need is a track record of users clicking on a link and rapidly backing out and then they can determine that the link is not a good reflection on the site
Danny Sullivan questioned Matt Cutts directly about that.
See [searchengineland.com...] for the details.
[edit reason] replace search term with link [/edit]
[edited by: tedster at 11:10 am (utc) on May 7, 2013]