To an extent I would say yes. If you register a trademarked domain it may be considered as cybersquatting which generally refers to the practice of buying up domain names that use the names of existing businesses with the intent to sell the names for a profit. The actual act of buying unused or abandoned domain names is not tecnically illegal but using the domain name in bad faith is.
In case of cybersquatting, the company can either sue to get their domain name and possibly some money damages under a 1999 federal law known as the Anti-Cybersquatting Consumer Protection Act, or they can initiate arbitration proceedings under the authority of the ICANN and win the name back without the expense and aggravation of a lawsuit.