I pray to God to be with me through this message.
Dear Bhavani,
You are right. It is copyright violation in this material world and Ramesh Babu ji may be sued. In the karmic world, it is even more. Ramesh ji, however devoted he may be to God, will accrue both negative karma of causing inconvenience to so many gifted singers and will also accrue some positive karma of sharing divine music with public. For Ramesh ji to reach God/attain salvation, he will need to work out both these types of karma which may take a long time or even several births depending on the intensity of the karma. Knowing or not knowing this will vary the karmic load, but cannot completely avoid the karmic load.
Similarly, people downloading these songs will also accrue negative and positive karma, which we too need to work out if we download. Downloaders can avoid this karma if we simply follow copyright laws.
Downloading is easy and we may want divine songs for emotional happiness or to use it for spiritual elevation without putting in the right amount of effort required to reach the divine. I believe it will be great if devotional singers, et. al. shared their God-gifted wealth, particularly with poor people. This way musicians obtain divine karma and blessings and listeners don't have to put extra effort in their spiritual pursuit.
Hope this helps.
snnn