[dm2]

Is it necessary to have used a service in order to comment on its policies? What if you just call a place and they are very rude, would it be ok to post that in a "review"?

I don't really see anything wrong with warning others that a hotel's policies are irregular and for people to be careful.

Just saying something such as "make sure you carefully read their terms before staying at this place or leaving a deposit, they are not standard and you could end up paying much more than you anticipated." might be justified, no?

Yes, I feel bad for the hotel, this could cripple their business, but it will probably make the news and encourage other hotels to review their policies. In the end the consumers (who are innocent) will be the ones who benefit from this.