The FCUK ('French Connection United Kingdom') company started it by being slyly clever with the intials in its name. Now all sorts of crass advertisers are using the word 'FCUK' as a cheap way of shocking the already sated young consumer into noticing their products.
Do I care?
I think I do. It's a low-level usage, and vulgar for the sake of it.
But then, it's only a word/spelling. Soon it will lose its power - and unimaginative advertisers will move on to other 'shock' tactics.