Recent unpleasant experience of Glassdoor in UK echoes what many other ONE STAR reviews have said here. Their policy seems to be to hide behind BS statements like "we are not the finders of fact" and admit that it is "often impossible" for them to know if a statement is true or not. Surely that means they know they are publishing lies.
My wife's company is being Trolled and certain senior managers being Cyber-bullied and Glassdoor defend this. Several posts are known to come from ex employees (out of date knowledge) (lack of awareness of new organisation structure) and contain pointed lies and insults. Providing a platform for behaviour that would be illegal face to face is highly questionable. Including character assassination in your business model is downright evil. There is a vast difference between criticising "the Management" and attacking a named individual. Glassdoor regularly lets that line get crossed- they seem to ignore the personal stress that causes. They may not bully themselves - but providing a platform and encouraging bullies is also bad. I think this company is morally bankrupt - avoid!