The Belzer Rebbe allowed kosher Smartphones but now the Chassidim received an SMS stating that WhatsApp is prohibited.
Apparently some Chassidim didn’t use WhatsApp in a kosher way despite the kosher smartphone.
I am not Belz and my smartphone is not necessarily kosher although I am not looking at porn sites. What I use is Twitter, the regular SMS phone service and sometimes Google +. What I don’t need is WhatsApp or Facebook and I cannot say that I miss out on anything.