…Blackstone Group (BX.N) has pulled out of discussions to buy part of Israeli mobile surveillance software maker NSO Group, according to people familiar with the talks that had been criticized by digital privacy activists.Two people familiar with the discussions told Reuters on Tuesday that the talks had ended without Blackstone and NSO reaching an agreement…NSO spokesperson Zamir Dahbash said the company was not currently in talks with any potential investors. Dahbash declined to discuss the talks with Blackstone or say why they had failed…