This article lays out some of the complexities of using a Geiger counter.
Some more false propaganda though to discourage the end user from being proactive in protecting themselves. Using a Geiger counter is simplicity itself to get some idea of the level of radioactivity in the local environment. Folks aren't interested in the radionuclide species or the whether the radiation is alpha, beta, gamma, x-ray, or neutron, positron, they want to know if the tomato on their plate in front of them is too hot to consume.