“ The Constitution does protect the freedom of speech of every citizen, and even of non-citizens — but only from restriction by the Congress (and, by virtue of the 14th Amendment, by state legislatures, too). There are plenty of other places where you could speak but where speech can and is suppressed. For example, freedom of speech can be and often is restricted in a work place, for example: employers can restrict your right to speak in the work place about politics, about religion, about legal issues, even about Desperate Housewives. The same restrictions that apply to the government do not apply to private persons, employers, or establishments. For another example, the government could not prohibit the sale of any newspaper lest it breech the freedom of the press. No newsstand, however, must carry every paper against its owners’ wishes. ”
Things That Are Not In the U.S. Constitution - The U.S. Constitution Online - USConstitution.net
