I was just applying for a job and was reading through the fine print at the end of the application. At the end of the fine print they link to a bunch of federal regulations that apply to them. None of the links worked but the top link was titled “employee polygraph protection act”, so I googled it. The US government is not a proactive institution so the reason this exists is almost certainly because, at one time, employers were using polygraphs on employes and it was so common and such a problem that the US government had to put a stop to it. It's not even like I have anything to hide but I am so thankful this exists.