Hello again. I'm getting the same message as soon as I click any hypertext. I wonder if it's an overzealous response to your adverts. The alert shows it's unhappy with 'http://match.adsrvr.org/track/cmf/rubicon', which from my non-expert googling makes me think it is some sort of code that matches ads to whatever page I'm on.
As with my earlier post, it's only a problem on Firefox - version 27.0, up to date. Running on Windows 7 Home Premium. On my IS software I don't get the same alerts.