Copyright
A copyright is the (usually exclusive) right to copy, perform and distribute a work that is an original expression of a idea for a limited period of time. The owner of a copyright can be an individual, a collective or a corporation. The default owner of the copyright is the creator of the work; however, under United States law, copyright can be transferred or, if the creator was creating his work within the boundaries of a work-for-hire contract, belongs to his employer depending on the exact conditions of the contract.
In the context of the Transformers brand, Hasbro and TakaraTomy are the main copyright holders for their respective markets, and they often even act as representatives of the other one in their markets. For example, an American who violates the copyright of something that technically belongs to TakaraTomy will have to deal with Hasbro, who will act on TakaraTomy's behalf. Since most official Transformers-related works are specifically created under work-for-hire conditions, there are very few relevant things Hasbro and/or Takara don't hold the copyrights to, and they will try to amend that as well.
A copyright is not the same thing as a trademark. Since copyrights affect original expression of ideas, it is generally impossible to "copyright" a name, term or slogan, otherwise the simple act of "copying" (i.e. writing it down in a public venue, such as an internet message board) or "performing" it (i.e. saying it aloud in public) would amount to copyright infringement. Names, terms and slogans are protected as trademarks, which are only relevant in commercial contexts. Unlike trademark infringement, copyright infringement can be committed by anyone; however, unlike trademark infringement, where the owner has to act as he might otherwise lose his trademark, it is up the owner of a copyright to decide whether he wants to pursue a particular instance of infringement or not. Compared to other companies, Hasbro and TakaraTomy have traditionally shown to be very lenient in this regard when it comes to taking legal actions against their own fans.
