From the article: > Others were encouraged to deposit cryptocurrencies such as ether into a “silo” to build up the stablecoin’s reserves in exchange for voting

From the article: > Others were encouraged to deposit cryptocurrencies such as ether into a “silo” to build up the stablecoin’s reserves in exchange for voting rights over the operation of the organisation. I’m not sure exactly what their reserves consisted of, but it could be mostly ether and similarly liquid currencies, rather than random ones. It sounds like the thing they stole was their non-random-currencies reserves that were supposed to be able to maintain the peg.