its all ready copy righted, this is more or less piracy.
How do you know that these are already copy righted? How would protecting MP3's on an MP3 player be piracy?
The OP stated that he/she created these MP3's so that doesn't mean they are copied music or anything. He/she could have made some voice recordings and changed them over to MP3 or maybe he/she recorded music that they wrote and performed and wants them protected.
Unless the OP states exactly what these MP3's were created from I guess we will never know.