I've never thought about that, but even if someone does get a head start they aren't going to win a prize. The point of the jam is to have fun.
How can you tell if someone had a head start?
I think he means since there's no prize for this jam, then it doesn't officially matter if they start early or not, it's just a matter of having fun by working within the jam timeline.
What aeroplane490 said ^
Ahh yea I see, but it would still be nice to have a theme...
there are many jams that have themes. You can pick from the lot :)
This is a special jam because of the restrictions.