If a work has been copied, altered, distributed, or performed/displayed without permission from the copyright holder or an exemption in the law, that copyright holder's rights have been infringed upon.
Deciding whether a work is infringing is not always straightforward, just as it's not always easy to tell a counterfeit from the real thing. In cases where musicians have been taken to court for copying another's song, both sides will call in expert witnesses with specific examples and comparisons.
If you are copying, altering, distributing, or performing/displaying something that is not your original work, and for which you don't have a license or an exemption, you are infringing on the rights of the creator.
In general, if you have used protected materials for which you have neither permission from the copyright holder nor an exemption in the law, you have violated the rightsholders' rights.
People who have broken copyright law are called infringers.
Rather a lot. What would you like to know?
You should always look for the copyright information. If there is none then you need to contact the author or owner of the material and ask them. Never assume. Most of the time though you'll see the license. It could be public domain, creative commons, copyright free, or copyrighted, etc, etc. Check the links below for copyright free resources.
It depends on the country. In the US, it would have been the 1831 Copyright Act.
UK copyright laws have been in place since the early 1700's
No songs have ever been sued.
In the US, since copyright law was amended in 1989, it has not been necessary to display a copyright notice for protection.
Yes; making a copy is one of the exclusive rights of the copyright holder, regardless of whether you sell the copy or not. Certain educational uses are exempt. It may be worth noting that while the law is broken whether you sell the information or not, the law may provide for higher penalties if you do sell it.
Copyright law is a federal law, granted in the Constitution.
Copyright law has been in effect for hundreds of years in most countries.
Copyright law.
The only person who can legally do anything about copyright infringement is the rights holder or his/her designated agent. That is who you should inform.