I think that people should have to stay with their blankets and belongings at all times (at least one person from your party) and you shouldn't be able to just leave them there. In fact, you're not allowed to do this already but people break the rules.
Last time I was there there was a blanket with a stroller in the very front row, next to me and another woman. It was ten minutes before the 9:00 showing, and the woman next to me had been camping for 4 hours and hadn't seen anyone touch the blankets. The Disneyland people got worried that it was a bomb in the stroller or something so they had everyone evacuate and so much time was wasted. When the people waltzed back to their spot, the Disneyland people talked to them and told them they aren't allowed to do that, but the people were allowed to stay.
I guess that's fine as they may not have known, but it was annoying as we were all inconvenienced by having to move all our
Seems like Disneyland should have someone standing by the Fantasmic! area during the day to help avoid this problem. If they see people putting down blankets and walking away, they could tell them the rule.
Or even more simple, how about a few signs along the gate of the river that have instructions like this:
Seating area for Fantasmic!
If you would like to reserve your party's spot early,
Please have one member of your party present
at all times with your belongings
All belongings left unattended will be removed