Can you sue someone for stealing your design?

Depends on what they copied from your original tweet.

No. You could possibly sue under copyright but only after you have registered your design. To maximize your damages this must be done within 90 days of the first publication of your artwork.

Were you first to complete the shirt with the design & text combination? Can you prove that the rapper copied your design and text? If both answers are yes - you might be able to sue - otherwise, no.

First a design on a t-shirt is protected under copyright law rather than patents. Second, you can sue the rapper but you will have to prove that he had the opportunity to see your design or hear about it in enough detail that he could copy it. It is possible for two people to create similar designs at the same time without having any idea about what the other one is doing. If that's the case, both designs are protected by copyright and neither designer can prevent the other from using the design that is similar to his.

With respect to t-shirt designs, an individual can file for a copyright which, among other things, gives that individual standing to sue someone else believed to be infringing on that design. Without registering the copyright, however, an individual can still obtain copyright protection albeit without the added benefit of being able to sue another for infringement. Such copyright protection is awarded once an expression is fixed in a tangible form such as a design on a t-shirt. Now, copyright protection does not prevent another from producing a similar or even same design on his own and independent of the other. In other words, if the individual created a t-shirt design that has "almost the same design and text" without directly copying the other, than there is no infringement. Regarding patents, t-shirt designs and most artistic expression of ideas are not patentable subject matter. In your case, more facts must be uncovered to better and more fully address you concerns. For example, did the other create his/her t-shirt design independently of yours? Has that individual register his/her copyright? If you were to register your copyright, which would allow you to sue for infringement, do you have any real measure of damages? (i.e. Would it even be worth it?) I'd like to give one bit of advice moving forward, though, and this advice everyone should heed. Do not publicize anything you wish to keep private, and when you do publish something, make sure that it has the proper protection beforehand so that issues such as these do not arise. Understand, too, that publishing or publication includes any social networking site where others are free to see it. If you have further questions, please contact an attorney knowledgeable in intellectual property so that you can properly protect your ideas.

Designs have value and are intellectual property. They are created by someone's intellect. Intellectual property is a form of property just like real property (your home) and personal property (your car). If someone were to steal your intellectual property, they have committed a taking just as if they had stolen your car. However, the taking of intellectual property is generally not considered a criminal act. The law provides a person with ways to protect their intellectual property. The ways are primarily Patents, Copyrights, Trademarks, and Trade Secrets. If a person does not protect his/her personal property, it's like leaving your car unlocked. I recommend that you speak with Intellectual Property Counsel about your rights. I hope that this helps.

The creator owns copyrights in the original work they have created from the moment the work is fixed in a tangible medium. However, if you create an original work that you want to protect you should consider filing an application for copyright registration. The advantages in doing so are that you have a presumption of validity in your copyright and you may be entitled to attorneys fees among your other remedies, i.e., damages, injunction, etc. Of course, to prevail in a copyright infringement lawsuit, you: (1) must own a valid copyright, (2) that someone else actually copied the work and (3) the level of copying amounts to misappropriation (substantial similarity). The facts stated in your case are not entirely clear. It is unclear whether your work is original or not. But, for the sake of argument, let us assume it is. Direct evidence of actual copying rarely exists. So, plaintiffs must typically rely on indirect proof of copying. Indirect proof can be shown if the defendant had access to the plaintiff's work and that the degree of similarity between the two works is so striking or substantial that the similarity could only have been caused by copying, and not, for example, through coincidence, independent creation, or a prior common source. Just because you posted something on Twitter does not necessarily imply that the "rapper" saw it and copied it. Furthermore, you really have no idea when the rapper created his "almost the same design and text". He may have done so before you, filed a copyright application all before going public when you noticed it. Finally, there is almost always a degree of subjectivity in the third prong of the copyright infringement test. So, there is an analysis of factors that must be performed to determine the level of substantial or striking similarity. Such factors may include comparing the complexity, uniqueness, or intricacy of sections of the two works. So, in conclusion, it would not appear that you have a strong case of copyright infringement, Patent law does not apply to these facts. But, you should consult an experienced intellectual property attorney to fully explore your facts scenario in order to make an informed determination regarding your rights. Finally, you should file copyright applications early and often. They are inexpensive and can give you many advantages if you have to go after an infringe.