This is NOT true! IMG is not a copyrighted format. It IS a disk container that is used by many different types of distributions. You originally developed Locus to specifically download copy righted maps and you got in some hot water for it but what would you expect? It's not same so please don't compare it to what you did. Reading an IMG map file and interpreting the contents is NOT legal, if you somehow built in a way to pull Garmin maps (IMGs made by Garmin) from some source then yes that would be illegal and breaking copyright laws. There are lots of applications that read and write IMG map files that follow the Garmin spec but but they are not breaking any laws and Garmin cannnot do anything as they are NOT circumventing any encryption. There are thousands of IMG map files that are not owned or copyrighted by Garmin and Garmin has absolutely no rights to these maps. Take for example PDF or DOC/DOCX files. One made by Adobe and another by Microsoft yet there are tons of applications that can read and write these formats.

This is your app and you certainly have the right to do as you please but please don't use some lame excuse as to why you won't add/improve the IMG format reading. If you are really that concerned about people loading up Garmin maps simply put a restriction in that will not load Garmin copy righted maps or put a disclaimer that the user needs to agree to in order to start using IMG maps. Here in the US about 90% of county recreational maps are produced in a IMG format and Locus is incapable of using these maps. I am a long time user of Locus and it really does have a lot of nice features. It's a great mapping program but the lack of IMG support is a MAJOR pitfall.

I really hope you at least do your diligence to research your rights for rendering IMG maps as if the legality of it is really what is holding you back there are a lot of Locas users missing out on a great feature in Locus because of your misunderstanding and lack of knowledge regarding file formats.