I haven't followed this much but I do recall that the weight budget for his "lawn chair" was over 300 lbs ... that's quite a lawn chair..
The biggest question in my mind is the sheer number of balloons. I think I read he was going to get 4 lb of lift from each balloon and had a total flight weight of 600 lbs, or 150 balloons. How are those tethered such that none are ruptured by another's tether rubbing against it?
When he shoots a balloon, shooting upwards would hit many balloons stacked vertically, also resulting in many tethers rubbing against balloons as the remaining balloons adjusted. Shooting to the side might not be practical either for that reason and for balance reasons.
In any case it sounds safer than
the Swiss guy who strapped on a jet engine and flew over the Alps outside of the intervals when the lawn chair is too low for parachute bail-out.
It's possible the deal with the slashdot problem, *if* you're willing to spend vast sums of money. I doubt SPOT has the budget for it, so they need to separate their business, marketing, and operations networks and internet presences, and be prepared to handle operations via FAX or phone in case of a DoS attack to reassure customers. That said, this was probably one of those cases where the cleaning lady went to unplug the vacuum cleaner and yanked out an Ethernet switch power cord instead...