Reliance on encrypted messaging.
They are both using encrypted messaging to organize, plot and attack their enemies, the chief common one being Donald J. Trump.
From the New York Times story
here:
They vetted each new member of the cell as Mr. Yazdani recruited helpers. They taught him how to pledge allegiance to the terrorist group and securely send the statement. ...
Because the recruits are instructed to use encrypted messaging applications, the guiding role played by the terrorist group often remains obscured. As a result, remotely guided plots in Europe, Asia and the United States in recent years, including the attack on a community center in Garland, Tex., were initially labeled the work of “lone wolves,” with no operational ties to the Islamic State, and only later was direct communication with the group discovered. ...
“If you look at the communications between the attackers and the virtual plotters, you will see that there is a direct line of communication to the point where they are egging them on minutes, even seconds, before the individual carries out an attack.” ...
One of the Islamic State’s most influential recruiters and virtual plotters was known by the nom de guerre Abu Issa al-Amriki, and his Twitter profile instructed newcomers to contact him via the encrypted messaging app Telegram. Among those who sought him out, asking for instructions on how to reach Syria, was Mr. Yazdani, who had convinced himself that it was his religious duty to move his family to the caliphate. ...
The Hindi-speaking handler guiding the men in Hyderabad also insisted on using a kaleidoscope of encrypted messaging applications, with Mr. Yazdani instructed to hop between apps so that even if one message history was discovered and cracked, it would reveal only a portion of their handiwork. As soon as Mr. Yazdani indicated he was willing to undertake an attack, the handler instructed him to download ChatSecure, a messaging app to be used when they spoke by phone. When he used his laptop, he was told to contact the handler via Pidgin, another encrypted tool. He was told to create an account with Tutanota, a secure email service. And the handler taught Mr. Yazdani how to use the Tails operating system, which is contained on a USB stick and allows a user to boot up a computer from the external device and use it without leaving a trace on the hard drive.