The majority of hacking programs that can ARO specify their burst in the active, and so presumably are Burst 1 in ARO, and look something like this: "In the Active Turn, the user may distribute two WIP Rolls among one or two targets." I want to know about Stop! because it does not specify the Active or Reactive turn: "The user may distribute two WIP Rolls among one or two targets." The only other program with more than Burst 1 in the Reactive Turn is Zero Pain, which explicitly states that it is used in the Active or Reactive Turn: "In Active or Reactive Turn, this program allows the user to make two WIP Rolls against the attacking Hacker." Is Stop! Burst 2 in the Reactive Turn? How do we know?
The general rules for Burst are defined as always dropping to 1 in Reactive, so without an explicit statement to the contrary simply follow that.
More importantly, the first two bullet points for Stop! are those problematic "Confusing matters by phrasing the program stats in English unnecessarily." :( A hacking program needs to look like Zero Pain to get B2 in ARO.