The requirements are for them to register with the State Department [if acting as agents of a foreign government], if memory serves, and with IRS for tax exempt purposes. Are there any other requirements? How much red tape is involved in such a registration? How frequently is the registration denied? The degree of control involved in the US is qualitatively different.
Planned Parenthood and other NGOs seeking to interfere in Russian society do Russians NO GOOD and they are aware of it thankfully. We too should be more aware.