Many of the problems that the SAT has had in this area have been the result of its tendency to reuse tests already given in the U.S. but not publicly released. That doesn't seem to be the problem here. The news reports don't say exactly what happened, but reading between the lines, it seems as if the security of some physical test booklets was compromised.
Traditionally, overseas students have been much more focused on the SAT than the ACT, which has always sold itself as being more tailored to a specifically American curriculum. As a result, the cheating rings have not devoted as much effort to the ACT. That seems to be changing. Could this be a knock-on effect of the revisions to the SAT shifting students' test preferences toward the better known quantity of the ACT?