A website called the Silk Road, is openly selling Cocaine, Crystal Meth, LSD, acid and marijuana to web users, in conduct that is highly criminal under U.S. law. The illegal drugs are delivered via U.S. mail, which is unlawful. The site has caught the attention of the U.S. Congress, which seeks to have the website shutdown. 

In this instance, Congress is well within its right to do so. Once a website so flagrantly breaks the law, under federal statutes, action can be taken to shut it down, as it is not a matter of free speech or free press. Drug dealing is illegal. Based on the fact the Silk Road originates from another nation, extraditions may ensue.