I'm in the process of making a javascript application and I want to bring that online, lets call it mydesign. I'm living in the Netherlands so mydesign.nl can be mine. Now is mydesign.com available for sale by some domain broker sales bastards. And those bastards don't accept a first bid lower than 1000$ which is a about ten times of the budget I'm willing to pay. So far so good, it's a sick business model but it's there. Now lets imagine that mydesign.nl is a huge success in the Netherlands and I'm makin tons of profits out of advertisements and other things I'm not yet aware of (I know entering the lotery gives a better chance of earning money, but lets just imagine). Is there a way (licence, legal or otherwise) to prevent the sick owners of mydesign.com to download and steal my javascript app and deploy it on their own site and take the profits of my app?
I am not a lawyer. (And I'm answering in the sure and certain knowledge that this question will get closed as off-topic.)
If they take your code and use it on their site and your code is not open licensed, that's a copyright violation and you have legal recourse. The first step is usually a Cease & Desist letter, and from there it's to the courts. Make sure there's a copyright prominently listed both within the code files and on the site's pages (in general, and again IANAL, you automatically have copyright, but let's be explicit) and indicate that all rights are reserved.
A Cease & Desist may well be all you need to do. Once it goes beyond that, be aware that it can become costly. But provided you keep good, written documentation of your business and the development of your code, you should eventually be able to prove your claim (which probably means recovering your legal costs, although the people you end up suing may well work through a shell corporation they can declare bankrupt, making it impossible to recover the costs). The question is whether you run out of money before that happens. :-)
Good luck.
Sure there's a legal way: sue the bastards if they do it. Might want to document your development process and make sure you have lots of people who can testify that you had the JavaScript app up and running on such-and-such date.
You could also obfuscate the JS code. That wouldn't prevent the other people from deploying it but would enable you to claim ownership by virtue of your having the non-obfuscated version.
You could also hide some code in the JS that would disable it (or parts of it) if it wasn't running on a page served from your host name. The other folks could change the code, but it would be a little harder if your code was obfuscated and there were multiple tripwires embedded in it.
Your JavaScript application is protected by copyright, and must not be copied for use on any other site. The law is on your side here probably everywhere in the world.
The question is whether you can take actual legal action over this if it happens. Most often, it's very difficult because the offender is in a different country, and you'll be spending hundreds if not thousands of dollars in lawyer and court fees before you even start to get them sued.
If you really have reason to worry over copying - I'm not sure you have, seeing as domain squatters try to grab any domain imaginable, it's most likely not an attack on your business idea - check out the various approaches to try and protect JavaScript apps... Not that any of those is perfect, but you may be able to do a lot, and make the stolen copy very hard to maintain, using clever obfuscation.
Oh and that reminds me... I'm off to grab stackexchange.de ;)