Obviously they are admitting this is the "worst app server tech", but seriously, since all of the communications are public and unencrypted, a rogue-agent could torpedo all entries by POSTing corrupt/meaningless data to the "output" endpoints during the calculation processing just by watching for properly formatted WASTE messages. A "correct" entry could then never be found.

Also, it could be the case that no combination of WASTEpoint steps could solve the problem (though they may tailor the calculation problem based on the registered WASTEpoints). I also wonder if some of the accounts may be suspended as spam mid-way through the contest?

This is an interesting idea, but I think the transport mechanism is too open.