An effective way for a government to indirectly prevent access to anything contrary to their political agenda, without resorting to outright censorship, is to limit access to public sources of that information. Sadly, my chosen homeland of Canada, under the current Harper government, has become a painful example of this.
Shutting down libraries with public access is one method that works well. Because science presents unbiased, evidence-based information, it is an important target for this tactical manoeuvre. A recent example is here: http://www.cbc.ca/news/politics/health-canada-library-changes-leave-scientists-scrambling-1.2499217?cmp=rss
But outright destruction of existing scientific research reports (effectively book-burning) is a related, more explicit method, exemplified here: http://www.cbc.ca/news/politics/fisheries-and-oceans-library-closings-called-loss-to-science-1.2486171
Of course, cutting research support that might threaten the government’s plans also works, and that too is happening. One shocking example is this. http://www.cbc.ca/news/canada/manitoba/scientists-angry-about-research-facility-closure-1.1212697
For fairly objective information on what is happening, here is the Wikipedia article: http://en.wikipedia.org/wiki/Experimental_Lakes_Area
For a quite accurate and witty editorial rant about this, here is Rick Mercer. http://www.youtube.com/watch?v=zU7dDruEWJE
Here is Rick Mercer again about the overall trend to muzzle scientists in Canada: http://www.youtube.com/watch?v=advh4xb6gRQ
And then there is also the attack on more populist sources of non-partisan information: public broadcasting: http://www.cbc.ca/news/politics/cbc-budget-cut-by-115m-over-3-years-1.1147096
We Canadians should change the opening lyrics of our National Anthem to “O Canada! / Our home and native land! / We mourn for thee!”
But I’m not bitter.