There was plenty of room on the 2/23rd flight, JFK to Kiev, however the 2/24 return flight was packed. That isn't ordinarily a problem except today, 2/24, there was a group of perhaps 2 dozen Rabbies, I believe, who proceeded to perform their religious rituals in full regalia, occupying isles, disrupting flow and with total disregard for others. They are paying customers and entitled to use their time effectively as they please, but they mobbed the flight, in the rear section of the plane. I don't know if anyone complained or if staff spoke anything to them. I was in row 33 today.The fact I was unable to use the interned even while WiFi was working was annoying.