My original reactions to it are in red (probably as was my face when I viewed it); additional comments are in black:
I do understand "flash mobs" require some planning to pull off the desired effect. The surprise is not in the "spontaneity" but rather in the execution. This is nothing more than liturgical abuse barely disguised as a pop culture phenomena.
And why was the local TV station brought into play? As Mary Jane pointed out, "...And I always notify the media before I do something liturgically spontaneous." You can't convince me this was not more deliberate that just what was claimed. If you listen to the adult interviewed, her justification for bringing it to Mass is lame.
And the pastor didn't know this was coming? Whether he did or didn't, this should have been halted in its tracks.They must be auditioning for a spot at the Los Angeles Religious Education Convention. Any bets you see that there in some form?
It was wonderful in its rightful spot, a talent show.
It is abhorrent during worship.
Another example of what someone has rightly labeled these kinds of abuses: "liturgitainment".