Citi Field, home of the Mets, is sold out for Sunday evening — but not for a baseball game. More than 40,000 ultra-Orthodox Jews plan to pack the stadium to hear about what the event’s organizers call the dangers of the Internet and how to use it in a religiously responsible way.

Tickets for the gathering have been so sought after that organizers announced on Wednesday that they had also rented the nearby 20,000-seat Arthur Ashe Stadium, home to the United States Open, for an overflow crowd.

Speakers at the rally in Queens will not seek to ban the Internet, but rather to raise awareness about how, unmonitored, it poses a grave risk to the community, said Eytan Kobre, a spokesman for the organizers. The risk, he said, comes not only from pornography, but also from social media and the addictive pull of the Internet, which can limit human interaction, reading and study.

“These are the same concerns that people across society — in academia, in psychology, parents, spouses — have about the Internet,” he said. “But here is a community that is actually standing up and coming together and putting our money where our mouth is, to express a unified communal resolve to address the issues.”