Answering a Hindutva group:
If criminals and drug addicts are converting to Islam and becoming good humans, then the credit must go to Islam; as they were criminals and drug addicts because of their previous religions and/or upbringings.
Having said that, who says ONLY criminals and drug addicts are converting to Islam? In fact, they are a tiny fraction of total converts. According to many western reports, hundreds of thousands of people are converting to Islam every year, and most of them are well-educated and decent humans. Poor and uneducated people usually convert to Christianity because of money and some other materialistic gain. Just go through the below link and see what type of people are converting to Islam:
They are much educated and smarter then you. And above all they are Westerners!
This is just a tip of an iceberg though.