I really like this domain name which I'm not going to reveal but a very big company currently owns the .co.uk extension of it and I like the name of it because it's really catchy and unique and the .com, .net, etc. are taken but I want to register the .com.au version of it, is it illegal/will I get introuble if I register the .com.au version of it to use for my company and run a exactly the same business as them? Thanks
Well, that's not really illegal but very dodgy as you run exactly the same business as them! They could argue that you're suing their name to promote your site. I remember Microsoft suing for mikerowsoft.com a few years back. Could be something similar.
If the name is trademarked, it could be a big issue. Yahoo had some success not too long ago with winning the rights to same name and similar name domains (yaho.com comes to mind...). If it's catchy but not trademarked, you should be fine. Is it located in the same country as you? I think honestly even if you don't develop a site on it, the domain could become worth something and you should probably take it if it's available and the company has some Australian audience. Just my two cents. Griffin
If you are in a different country than the U.K., the trademark doesn't apply to you. However, ICANN domain law still applies and your name could be taken away that way. I think you would be taking a heavy risk. Just come up with a unique name. It will be better in the long run.
The legal analysis is as follows: There are no "trademark police", so if you mean trouble in that way it won't happen. But extensions like .net, .com., .uk are all generic identifiers that are ignored for purposes of trademark infringement analysis--a court simply removes the extension when running an analysis. The risk is a cease and desist letter from the owner of the mark. My suggestion would be to not throw any effort into it. If you get big enough, they'll find you...
Actually the risk is getting your pants sued off, but that's really a worst-case scenario. I do agree that unless the sites are fundamentally different, you really shouldn't bother developing it. Buying it is another matter, as most sites like these are purchased from the domain holder for a decent amount. I would suggest buying it and then immediately contacting the big-name site and offering it to them for a profit. You can also try parking it for a bit and seeing how much you might make in ad sales, but if it's the difference between .com and .com.au, it would be a bit of a stretch. But you can buy and then sell it to the big-name site owner for a decent profit (with a ~$10 investment).
The "trademark police" are the owners of the trademark. If this is a big company, they probably have a trademark on the name. Developing the site to be in competition with them will get your domain taken from you when they notice it. Not developing it and contacting the business to sell it to them will also get your domain taken from you if they know anything about the process. Any of those ideas break the ICANN guidelines. The only thing you can legitimately do with that domain is to create a completely unrelated site. Otherwise, the likely best scenario would be that you lose the domain and any work you put into it without any compensation. Worst case, you face a lawsuit and fines that can run into the tens of thousands or more.