It's not that easy to obtain peroxide in high concentration, though it is possible for industrial usage. The stuff you buy in the drugstore is 97% water, and even the kind used for hair coloring is at most 12% active (88% water).
But I bet peroxide will now go on the list of substances for industries to track.
Go to a swimming pool supply company. I am not certain, but if memory is correct they have some peroxide solutions that are in the neighborhood of 90%. Use only a couple of gallons in a 20,000 gallon pool.
The highest I have seen is 70%. I think though that what would be used would be organic peroxides which are very unstable - which could be used as an initiator. They can be set off by shock or heat. And yes, they are easy to get if you are in the chemical industry.
Yes, apparently it was a very strong solution of peroxide and the other part was sulfuric acid, to be set off with batteries from the flash of a disposable camera.
http://www.deadiversion.usdoj.gov/pubs/program/sotf/appendixa.htm
It already is watched, by DEA.
http://www.atf.treas.gov/pub/fire-explo_pub/listofexp.htm
And the peroxide explosives are watched by BATFE.