There are rules about distribution regarding print media. Some material is deemed "not appropriate" for certain age groups. This is a form of censorship based on a moral principle.
Other censorship also exists regarding hate speech and speech that openly incites violence. This censorship applies to print media.
The internet really cannot be censored, but it also should not be a double standard to be censored more than the print media. If you are talking about pornography, I think the idea is that you can control who buys it more easily in print, whereas kids can find it by accident online.
One of the most detrimental forces against free speech have been the unwritten laws. As mentioned above there is "self-censorship"; in addition, there is what is euphemistically termed "politically correct" speech and wording.[ By whose "politics"are these guidelines made, by the way?]
One of the great Americans of old, Henry David Thoreau wrote, "That government governs best that governs least." Unfortunately, with the plethora of irresponsible people, some governments are moving stealthly toward police states and individual rights and privileges are being eroded.
With the criminal element increasing, what can be done to protect national security? Franklin Roosevelt was correct when he told Americans in the 1940s that the greatest thing they had to fear was fear itself. Out of fear comes censorship and "patriot" acts--and even dictators.
To some degree, there is self-censorship of print media and has been for a very long time. For example, there are obscene words that are not printed in mainstream publications, and most reputable newspapers will not publish the names of minors victims or offenders or of rape victims. This is, of course, not political censorship, which would run afoul of the First Amendment of the Constitution. Nevertheless, there have been times when news has not been reported, at the request of the government, in the interests of national security, for example. In earlier times, pre-Watergate, I would say, newspaper routinely chose to not report news on the personal lives of politicians, for instance, the mistresses of presidents such as Roosevelt or Eisenhower. We tend to think that there is no censorship at all of the print media, but there is still more self-censorship than we think about and occasional censorship from the government.
As far as I know, we don't censor the Internet, do we? It certainly doesn't look censored!!
I suppose that for someone wanting to censor the Internet a case could be made for how pervasive, fast, and anonymous it is. Just about anybody can read or post anything at anytime.
For those following the CISPA bill in the Senate, we are on the cusp of internet censorship under the guise of "protecting" us. It is a very real threat, although it is not being seen in mainstream media outlets.
Google is heavily involved in censoring the people of China's access to information and some would argue that they may be doing the same to the US and elsewhere. After all, Google is working with the NSA to spy on us (Court rules that Google-NSA spy ties can remain secret). A subtle usurption of what becomes accesible is not a far-fetched theory once you are open to what is going on.
As far as print media goes, I contend that it will be a slippery slope once CISPA passes the Senate (Obama is itching to sign it into law and even threatened an Executive Order to override). The fact is we have been slowly giving up our rights in the US to our "protector" goverment. Benjamin Franklin said, "Those who would give up essential liberty to purchase a little temporary safety deserve neither liberty nor safety."