In the film The Purge, the rule says:
In 2014, the New Founding Fathers of America, a totalitarian political party, are voted into office following an economic collapse. They pass a law sanctioning an annual "Purge": for 12 hours each year all crime, including murder, arson, theft and rape, is legal during the period, except against government officials, and all emergency services are unavailable until 7 am.
If you're a hacker and build a program to execute in these hours that gives you total control of the country, creating a new government role like "emperor" above the rest of the party, you aren't doing anything to government officials and, because you're a government official yourself, no-one can attack you.
Is that possible?