The "approved" way to do this (in the United States and other Communist/Fascist Regimes) is to set a flag somewhere that "authorized" applications obey. You can then use the DMCA to sue those who would change or disregard the flag as being "unlawful circumvention" and those who publish details of how to change the flag setting as providing "illegal circumvention technologies". You should then also embark on a massive advertising campaign against "illegal circumvention tools". This is the Communist and Fascist Approved method of control. In other words, once you have let something out of your physical control, you no longer have physical control. Sorry to tell you that this is how the universe works, but it has always been thus.