Legal protection for ideas and inventions is a matter of civil torte law in the United States. The law only allows you to sue for compensation if you discover a violation of a copyright or patent violation. Vigilance is how to legally protect your business idea under the law.
As far as patent protection goes, the first responsibility that you have is to obtain legal recognition that the idea is yours. This involves what could be a rather long and multi-step procedure including a description of your idea or invention in detail with documentation as to how it works, a thorough search through patents going back hundreds of years to document that the idea is original, selecting a patent classification using the patent office's classification code, then waiting for approvals.
Written or artistic work is considered to have an automatic copyright as soon as the work is written and fixed in a permanent or recorded form. Proving that you are the first author has occasionally been a problem, particularly with successful song lyrics and melodies. Several well publicized law suits have arisen over claims that sections of music or parts of written work have been stolen. It is all a matter of torte litigation when that arises.
The question for many entrepreneurs is how to find funding for their new work, invention, or written creation. A growing number of inventors have turned to crowd funding as a mechanism to raise support where venture capitol funds or lenders are not available. In 2012, about 320 million dollars worth of donations were raised for the development of ideas through Kickstarter, the largest of dozens of crowd funding sources. Crowd funding does involve certain risks that test the limits of intellectual property protection law.
New legal questions have arisen as the ownership of crowd-sourced projects and disputes over the possibility of copyright and patent protection for crowd sourced projects. If, for example, you prematurely disclose your technology on a crowd-source site, you may enable someone else to legally copy it. The idea may no longer be patentable or you may lose any copyright. New patent laws in the United States give patent rights not necessarily to the originator of an idea but to the person who makes the first patent application.
Then there is the issue of fraud lawsuits. If you receive money to support the development of an idea from a crowd source site, but then fail to deliver the finish product even if you encounter problems in the development of the idea, you may be subject to individual fraud lawsuits.
When starting your business, it is a good idea to be aware of anything that might threaten your company's future. While you want to plan for the best, as always, it's prudent to prepare for the worst, or at least the bad.