If the site where the form was filled out sets the users' collected info as rather obviously-named Javascript cookies or PHP session vars (i.e. $_SESSION[email]=$_POST[email]), that's one method, no?
Was anything mentioned about the browser used? Maybe when "auto-fill" browser options are enabled for a user there's a way to access that data.
Was anything mentioned about the browser used? Maybe when "auto-fill" browser options are enabled for a user there's a way to access that data.