Hijacked traffic is the dream of any webmaster. By doing nothing, you receive free traffic to your website. And this often means good money, although the monetization very much depends on the volume, nature and language of the traffic you receive. Just imagine that with a few dozens of good domain names, you can probably stop working forever... Is it legal? Yes, as soon a this does not fall into cybersquatting. Is this moral? Difficult to say. But to give you good conscience, you can always think about that the biggest traffic hijackers in the world are Microsoft & Google. A significant part of their turnover (20 % ?) is achieved without any effort, by just redirecting IE & Firefox web users to their search pages, respectively Live search & Google, of course with ads, as soon as the url typed in the address bar does not resolve.