"Well, you can't have a minyan online. You cannot have a quorum of ten people."

I don't understand this. I fail to see why ten Jewish men can't meet in a real time chat room online and thus constitute a minyan - the minimum number, according to Jewish tradition, necessary to pray and worship communally.

"That's very interesting. Why not?"

"Because the quorum of ten people requires ten physical bodies. Each individual person has a spark of G-dliness within them, which is the soul. It requires the quorum of ten people, which reflect the ten different levels of G-dliness. So therefore you can have nine people who might not be religious at all, and one person who is religious. Their religious commitment doesn't matter, as long as they're Jews."

"And male." Daisy gets in.

"And male, over the age of thirteen. But the concept is that if you have those ten people, you're bringing down a high level of G-dliness that will allow you to say the Kaddish prayer."

"But why," I ask, "can't that take place in a virtual chat room with ten males?"

"Because there's no physical presence. We don't necessarily see the spiritual reality of what is happening at the time, but certain things have to be done with physical people, just as food has to be eaten by physical people."

http://www.chabad.org/library/article_cdo/aid/335578/jewish/The-Soul-of-Cyberspace.htm