As of the year 2019, this imprint has been used on a global scale, transmitted through phone lines and other types of technology, regardless of whether or not the recipient has the active architecture or not. After being imprinted, the individual became bloodthirsty and violent, attacking and killing others, such as actuals and dumbshows. (S1: "Epitaph One"; S2: "Epitaph Two: Return")
By the year 2019, the butchers have wiped out so many non-butchers that they have begun to hunt each other for food, and it is still possible to be imprinted as a butcher simply by walking past an active piece of technology such as a boom box ("Epitaph One"). The growing competition for resources has caused a sort of natural selection process to take place, and thus some butchers have demonstrated a capacity for more complex tactics, including using firearms, climbing ropes and working in groups.
It has yet to be revealed who is the source of the imprint or it being used on a global scale, thereby making it either the Rossum Corporation or someone else. It's suggested that it was the Rossum Corporation, given the statements made by Clyde 2.0 in "Getting Closer" and the status that Clive Ambrose and Matthew Harding enjoy in Neuropolis during "Epitaph Two: Return". It is also possible that it was someone else, as suggested by Boyd Langton, the inevitable result of the wrong group(s) getting a hold of the technology. This is indeed feasible, given the known existence of at least one rival company, Bel Med Tech.