The problem is, the current law isn't match the pipe analogy. If it's a private communication, they can be a pipe. But they are publicly present the information

The problem is, the current law isn't match the pipe analogy. If it's a private communication, they can be a pipe. But they are publicly present the information as soon as it gets to the pipe. There are many expressions you can't publicly present by law. For example, copyright infringement, privacy infringement, pornography, national/personal/organization secret, fraud, malware and all. You may argue some of them are ridiculous, but there are some expression you agree to be supressed. Like the fake news of you committing the crime. Yes, In an ideal rule of the law world, you should take the court order to censor that expression. But it takes time. The current law is, if you knowingly publish the material that is obviously illegal and ignore the censorship demand, you are responsible for that.