Who is Saleem Wastik, ex-Muslim YouTuber whose throat was slit in UP?

Saleem Wastik, whose throat was slit by two men in Uttar Pradesh's Ghaziabad, runs two YouTube channels and has appeared on multiple television programmes. On his channels, he goes by the title "Ex-Muslim". Wastik has previously been in the news for statements critical of the Muslim community and aspects of Islam following his renunciation of the faith.