Question Summary:
Can a mobile used for haram render salaah invalid?

Question Detail:

Hazrat, I wanted to ask if someone uses their cell phone for haram – for example to watch pornography, or speaks to non-mahram women, and has the phone in his pocket whilst performing salah.
 
Is the salah valid?

Answer :

Yes, his Salaah will be valid. However if the phone in his pocket will distract his focus and attention in salaah, then he should keep his cellphone elsewhere.[i]
And Allah Ta’āla Knows Best
Aboobakr Siddeeq bin Mufti Amjad Mohammad
Student Darul Iftaa 
Azaadville, JHB, South Africa 
Checked and Approved by,
Mufti Ebrahim Desai.