Question to JMI

Sometimes I am very careful about what I post here, but I see that many people are not so careful, but I am wondering how safe it is to post stuff here?

Say if company 'X' didn't like someone's post and they demanded that you give them the poster's IP, would you give? Or since the server is in China they have no rights to the IP?

How secure can we feel about posting stuff?

Thanks.