Mobile phone "addiction" has even penetrated the strictly Orthodox Stamford Hill community, prompting religious leaders to ban their use in synagogues.
A declaration has been signed by the Union of Orthodox Hebrew Congregations Beis Din and more than 60 Hackney rabbis and school heads.
Community leader Rabbi Avraham Pinter said the issue was becoming a problem.
"People have now become addicted to their mobile phones. Even if the phone is turned on to silent, they feel the vibration and they have to look at the message. Even if they don't reply, it's not compatible with the sanctity of the shul. It's vital nothing should disturb it.
"I have even heard of synagogues looking into ways of blocking phones from having a signal in the building. When you are in shul, the best place for a mobile is at home."
The UOHC directive permits phones to be switched on only in an emergency - and then on the silent setting. It points out that "while nobody would have ever thought of stationing a public telephone inside a beis hamidrash, reading a newspaper or opening one's post there, the small hand-held device that carries out the same function has been gradually finding an acceptable place".