Not that, but general spying on people/invasion of privacy whether in the name of fighting terrorism or in this case the people at Pak Telecom Authority say its because people have complained about receiving obscene text messages.
Btw, I'm not for this ban at all but sms'ing is on a whole 'nother level there...
even beggars (no joke) own cell phones and people are so obsessed with pimpin' their phones out that they'd rather not have any money for anything else but be able to afford to buy custom ringtones, custom dial-tones(!), skins, etc. And you can't escape spam text messages. I was there for a month and I got dozens of spam text messages. Some dude who met my cousin like once or twice, got his number and wouldn't stop sending him love poems...which apparently isn't considered gay

Anyway, I can imagine the 'obscene' text messaging does really happen but a ban is bs (read it's been delayed).