Anyone have any idea?
Yep, but most of them involve blunt, rusty objects so I'll hold my piece.

Only
ethical thing I could suggest is going down the trademark type route in court etc. Not sure how quick/successful this could be (I'm guessting , 'not very') especially as I'm guessing the domains are registered by parties 'over-seas'.
Unfortunately, I think this is likely to be something that just 'happens', at least until user training/awareness is at a level that people spot these sites, realise they are in the wrong place and re-type the URL. At which point the commercial gain from running the sites should take a hit.
None of this is likely to help your particular situation any time soon though, sorry. From similiar experiences I find these are 'grin and bear it' moments. Hopefully you can prove me wrong...