Recently www.theknot.com featured a blog post about guests taking pictures during the ceremony - check it out here: http://blog.theknot.com/2013/10/07/wedding-guests-camera-etiquette-what-not-to-do/
As your wedding minister/officiant I know that we have worked so very hard to not only write the perfect ceremony but to plan who is sitting where, what music would be best and what positions work well for photographs and really just thinking of every detail possible.
I personally have no issue with guests taking photos during the ceremony. However I have noticed that with so many wonderful phones that have great camera's it seems every guest is set on capturing "the photo". While this is really sweet and I'm sure comes from a place of love...it may not make for the best photos for your professional photographer - you know the person (s) you spent so much time finding then interviewing and not to mention PAYING...well, it's hard with every guest angling for the best photo for your photographer to get the best picture for you to have for yourselves. I mean think about it...your hoping and dreaming of this photo:
But instead end up with something close to this