Why, in that case, did they not defend their name against he previous owners of the cloud domain ?
I have the same exact situation with my own company. I own the .net analogue of my company's name, and someone owns the .com. They've owned the .com for several years, and have a 10-year registration according to GoDaddy. The site currently doesn't do anything - it doesn't resolve at all.
The best thing to do in this case is not to approach the person, but establish yourself and make the name worth something. Then, the cybersquatter will attempt to monetize the name and hopefully do something which can be used in a UDRP claim against them, like setting up an advert site or something.
In any case, it appears the trademark was owned by someone else and maybe iCloud didn't want to pay up. You can't go based on domain names at all - you have to use established business use as the guideline.