"Patrick Lin, who led a study this year for California Polytechnic State University on the ethics of hacking back, said there is "a moral case for hacking back, but an under-developed case for its legality and effectiveness."
In the report, Lin wrote that while it is difficult to know whether hacking back has deterrent value, "doing nothing, as seems to be the case now, certainly offers no deterrence and likely encourages cyber-attackers to continue preying on others."