Wedding stalking started at the NZWP site...we would put either private invites or in many cases - open invites on the forum for other members to come and watch our weddings.  
We kind of termed it "stalking" as a bit of joke really.  In some cases we got to know each other so well people got full invites.  I had a stalker outside my wedding but she chickened out and didn't come in. One of the other members was going to stalk but got a full invite and we are now close friends.
OMT stands for Old Married Tart - what you become when you get married!