Hire Lawyer to Certify a Public Domain Work
Each time you use a public domain work in your business, you should consider get the work certified by the copyright office. The next question then is whether must hire a lawyer to do it . There are plenty of “research” work and copyright controls that you can perform yourself (or pay someone to carry them out for you) without having to go through legal hassles.
In the end, you only need an attorney if you violate the copyright. Even then, certain gray areas where the law is not so clear, and his own interpretation could be disagree with the Court’s interpretation, which puts him in hot water.
So take the case of the situation on a case by case basis. If you are sued, you definitely need a lawyer. Apart that, the best bet is to stick to ensure the public domain. If you can verify with sure that the copyright of a work has not been renewed (if the book was published before 1964), then surely be considered public domain. Similarly, if something is published without a copyright notice before 1978 is in the public domain.
The only glitch comes when starting your own derivative work of another property work or a work whose status can be determined through research. There is also a problem by working with unpublished works. In these situations, it is best to maintain a counseling session with an intellectual property attorney before taking any final business steps.
Many people are put off by the high cost of attorney. On the other hand, you have to weigh all the costs (research, control of copyright, legal fees, production, marketing, etc.) against their expected benefits and then decide whether it is worth the investment or not. If murderer to find a niche that could easily carry a high monthly income, perhaps spending a few hundred dollars to protect against litigation is not so bad after all.
Copyright issues are raised only for works that are unpublished and published works after 1922. I suggest you start with pre-1923 published works, even if they bring smaller benefits (the idea is to create multiple income sources). Then once you have a constant income stream, you can make larger investments and move to the unprecedented and the later works of 1922.