Is it legal to create a website based on a real company? For example, creating a website based on Nike and talking about how it is really good or really bad. Could Nike say anything legally?
So long as the URL isnt similar and you ensure that you put the required text at the bottom stating that any nike imagery is nikes property, etc... then thats fine. However, avoid having the company name in the domain name itself that could really get a companys back up, such as a domain name similar to "nike-make-crappy-shoes-and-exploit-slave-labour.com" wouldnt be the best idea. If the sites intention is to slander, allow users to review nike then id be sure that you have your ass covered in every possible way, get consulation from a lawyer that specialises in this sort of thing, as review sites are used by mostly one set of customers, thats the customers looking to buy, and the customers that have bought and are pissed off so they want to shout about it.
on a positive side, having a side called ilovenike or nikeisthegreatest maybe could be tolerated, so long as you didn't infringe their PR.