There have been several variations on the theme. Some of the Mass Mobs are organic and are led by fully grown 'meddlesome kids', such as the first Mass Mob and us. A number are more clerical in character. Detroit has full archdiocesan approval, help, and participation, and the Knights of Columbus (who also organise South Bend's). Some are an addition to youth ministry. Other cities have a seminarian, deacon, priest, or other diocesan employee as organiser.
The model was developed in Buffalo using 'social media' to stage a mass gathering at a Mass. But really, the success was getting broadcast media to report that 'social media' was the engine. This proved itself in Cleveland's first mobbing. Buffalo's mob committee had friends in the press after years of municipal activism. Some have used very little promotion, and have had modest results follow. Facebook is the most popular vehicle of announcement, yet in some cases it is hard to find them there.
This movement spread in two mini waves. The first after the story became national through an Associated Press article describing Buffalo's second mob. The other wave was after a New York Times article describing a few of the mobs, with a dateline of Cleveland. "Mass mobs seek to draw large crowds to a single church in a demonstration of support for Catholicism and its most beautiful — and often needy — churches." Certainly this describes the majority of the mobbings, but some have different rationales and visitations. Three locals chose their cathedral church, the seat of the bishop, the one church which in their local is immune from certain parochial problems; one local being where the bishop has been convicted of criminal behaviour. That sends a message too.
Enthusiasm, organisation, and style vary from local to local. Some did little to nothing in going forward, some are more recently declared have only a static facebook page. A few called a 'mob' for their parish, and that was the totality, and were never meant to be a local mob.
Rochester's two founders attended Buffalo's Mass Mob II and have been the only local to go beyond a Catholic tour. They very early explored the idea whether this event of ecclesial enthusiasm could be exported ecumenically*. Their first mobbing was at an Unitarian-Universalist church. They received some local media interest, and held a second mobbing at a Catholic church. Interesting, but disappointed in attendance and the degree of effort exerted; they retired. The one fellow attended Cleveland's second mobbing. He saw at least four mobs in three cities. I have no second example of this.
Buffalo, Cleveland, and Detroit have beautiful ethnic parishes and churches to mob. Detroit has huge churches. Some of the other cities have mobbed non-architectural splendors, and have made no mention of national character of congregations. In those mentioned and some other locals, Polish parishes were mobbed. Here in Cleveland, we mobbed ten churches and four were Polish parishes, and the attendance ranked 1,2,4, and 5.
Both Buffalo and Cleveland had recently suffered from parish closings, Buffalo belatedly received diocesan acceptance of the mob. Now, New York City proper is in two dioceses. Currently, the archdiocese of New York (has 3 of 5 boroughs) is reducing parishes. New York City has had a popular vote for the four mobbings they have had. The last one was at a parish that is gallantly fighting to survive forced closure. So a focus of some of the mobs is not just to attract attention, not novel evangelisation, but to celebrate the continuance of a church and parish against arbitrary misfortune.
Cleveland has not had a mob since All Souls Day, and still leads in number. Throughout the upcoming year Cleveland and Detroit will continue at the top, with Buffalo, and Pittsburgh right behind. Detroit's mob came together from separate nuclei, and since has had outstanding success. Now a member of their mob has started a second mob. Fort Wayne and South Bend share the same bishop.
Cleveland is the only mass mob to mob on a weekday. The Feast of the Assumption was on Friday, and we had a great turn out at St. Mary Bedford. Cleveland has had the only mobbing of an Eastern-rite church, Holy Ghost; and this is the the church that the New York Times correspondent came to, and wrote about. Earlier the paper had sent a writer and photographer to St. Michael's.
Cleveland had five churches mobbed that were once closed. Only Detroit went to another formerly closed church, St. Albertus, and it is outside diocesan management. That and other Detroit mobbings had Masses said by bishops.
Other odd notes: Covington announced a mob and didn't have one in the first year, and came back as Greater Cincinnati. Saint Louis has six mobbings scheduled, two in 2016, and has not have one completed. Their first mass will have their bishop presiding. Most locals do not announce, or even know where they will mob beyond the next one. Detroit after they merged had the year planned out, and their two mobs now both have this year planned and public. Pittsburgh had future ones announced, and had nearer in time announced later. Philadelphia deferred to their archdiocese to such a degree that an impression was given that mass mobs were an episcopal creation. Philly had two mobbings and stopped without a note. Greater New Orleans was the first to go to a suburban church, and had one more mobbing, and also stopped noting. Wilmington was dormant, and recently held their first mobbing with very little notice. One mob, Rural Davenport, is planning for rural churches. Memphis has a vote, and announces some four days before the mobbing.
*The ideas of community in a sacred space and local pilgrimage makes sense within Catholicism, i can not see other groups in the United States being interested participants.