GlassDoor has been gross about this for years.
Not sure if still the case but normally you have to not only 'sign in' but also feed them information (e.x. salary at a position, write a review, etc.) in order to be able to view much of anything.
They also do not give a shit about obvious 'juicing' (i.e. when it is obvious that upper management and/or HR is adding reviews where the 'con' reads like one of those softball warning phrases in a job description.)