Controlling internet content is controversial and difficult. Why?

Can you give me any examples that i can refer to so that i can look at the law behind the internet and content regulation and justify the ethical arguments.Controlling internet content is controversial and difficult. Why?
As the Internet is a place of ideas not someones perverted values who think they have a hot line to God NOTHING AND NO ONE HAS A RIGHT TO BAN ANYTHING PERIOD..... You do not like it go somewhere else where u can violate freedom. Say North Korea, the US oops, LET ME OUT OF HERE.Controlling internet content is controversial and difficult. Why?
There is no central entity that information must pass through before getting on the internet. Anyone with an internet connection can post pretty much whatever they want at any time, and not have to worry about some censor catching them.
The main reason why it's difficult to control, if not impossible, is that it's worldwide. What's illegal in one country may be legal in another.
where ever you look there are rules. keep off this, don't do that etc etc. the Internet should be a free world for the people to enjoy. no one should control any thing. there is too much control. too many fences. and always!! plenty of reasons to throw some barbed wire around any!! thing that stands free. governments hate!! what they cant control......they have to have their greedy perverse little say in every thing.
Yahoo Answers seems to be a good argument to your first statement.
google is your friend. keep the word ';china'; in your search. or ';saudi arabia';.
It is such an easy way to get views and opinions across to an extremmely wide audience. As there are billions of pages, imagine having to censor all of them.