Body armor is illegal to purchase in NY, unless you are a security guard or the like.
Not sure of the reasoning, except they want people to be easy prey.
Penal Law Section 270.21
Unlawful purchase of body armor
“A person is guilty of the unlawful purchase of body armor when, not being engaged or employed in an eligible profession, they knowingly purchase or take possession of body armor, as such term is defined in subdivision two of section 270.20 of this article. This section shall not apply to individuals or entities engaged or employed in eligible professions, which shall include police officers as defined in section 1.20 of the criminal procedure law, peace officers as defined in section 2.10 of the criminal procedure law, persons in military service in the state of New York or military or other service for the United States, and such other professions designated by the department of state in accordance with Executive Law ยง 144-A (Eligible professions for the purchase, sale, and use of body armor). Unlawful purchase of body armor is a class A misdemeanor for a first offense and a class E felony for any subsequent offense.”
https://newyork.public.law/laws/n.y._penal_law_section_270.21