I've been looking at different plan options for my mobile and came across this in the Socialser conditions.

There are other instances where Socialiser can't be used and charges will apply. This includes the following:

The use of voice and video call features
External links in newsfeed, timelines, walls, etc.
External URLs in comments, messages, etc.
Links to applications
Links to external advertisements
Enabling or navigating to features that rely on location services
Facebook features that navigate you out of the site and/or application such as Get directions, Buy tickets, etc., and/or importing contacts from an external email domain, clicking on a user's email address and so on
Background camera app usage on Facebook
Pages Manager apps on Facebook
Using the Opera browser on Facebook or Twitter on your mobile

I can understand the limitations on external URL's and links etc but I'm curious why they discriminate against Opera browser? Not that I'm a user of either Facebook or Twitter but I am a fan of Opera. I'd have though this limitation would apply to any browser.

Anyone have any ideas?