Cybersquatting is when a person registers a domain name on the Internet that is identical to a trademark for which they do not possess ownership.
The goal of cybersquatting is to attempt to force the trademark owner to pay the domain name holder in order to get the domain name. Cybersquatting is illegal and considered unethical.
People who attempt cybersquatting can find themselves facing a lawsuit from the trademark holder. For example, if a well-known company is named J.S.T. Shoes, and a person who is not the owner of J.S.T. shoes buys the domain name JSTShoes.com, this would be cybersquatting, and could result in a lawsuit.
Cybersquatting is very similar to trademark infringement. However, it is less of a concern now because companies are much more aware of the need to purchase domain names corresponding to their trademarks.