Public Internet, Freedom of information?

How would most people feel if someone walked up to them and said they
couldn't look at the Mona Lisa or other works of art, or that they
could no longer read certain bits of news because they were to graphic.
Most people would not stand for it. So why do so many people let the
government and public facilities install programs to sensor what they
can and can't view on the Internet.
There are many programs that have appeared recently to "protect" young
and more sensitive people from certain topics on the Internet. However,
the largest portion of these programs not only keeps people out of smut
sites as they are supposed to, but also sites involving legitimate
information because of words in the title. (I.e. Research on breast
cancer and other sites with words that have been designated
"Restricted") or disallow viewing of any site that has not been rated through
their system. This may be fine for personal computers where parents
decide that young children might stumbl...