Interestingly, the people doing this are barelvis(sufi inspired hanafi sect). They are the most militant when it comes to blasphemy killings. The killer of Salman Taseer belonged to the same sect's dawat-e-islami movement. According to observers, they're trying to lure in more followers from the extremist element by conducting such acts.
The barelvi sect is also highly anti-Taliban and salafi movements, for barelvis accuse them of disespecting the prophet(SAW); which Salafis do indeed. The first militia uprising against Taliban in the Swat valley was by a local Barelvi pir. In Tirah valley, the Barelvi militants hasve actively fought the TTP and Lashkar-e-Islam. A Barelvi militant organization, Sunni Tehreek, holds a small turf in Karachi, and has assassinated a number of Taliban supporters and clerics there.
The barelvi sect is also highly anti-Taliban and salafi movements, for barelvis accuse them of disespecting the prophet(SAW); which Salafis do indeed. The first militia uprising against Taliban in the Swat valley was by a local Barelvi pir. In Tirah valley, the Barelvi militants hasve actively fought the TTP and Lashkar-e-Islam. A Barelvi militant organization, Sunni Tehreek, holds a small turf in Karachi, and has assassinated a number of Taliban supporters and clerics there.