Fred Olsen fuel surcharges - Are they being unfair again?

A few months ago I wrote a blog about Fred Olsen imposing gratuities on their guests automatically, (you can read the post here). I thought it was a bit unfair of them at the time but since then I've not hear much from them. There latest move however strikes me as really unfair!
A couple of my colleagues have blogged recently about the Fred Olsen fuel surcharges currently being added to existing bookings.
For those of you who don't know, because the price of fuel has risen so much in the last few months Fred Olsen have been contacting passengers who have already booked their cruise and adding a fuel surcharge to their bookings. If I'm going to be honest with you that's all passed me by a little.
Yes I think it's a little unfair that Fred Olsen are doing this to passengers that have already booked but it is in their Terms and conditions.
However........