Actually we have been fortunate enough for the past 25 years to enjoy a fairly good level of freedom of speech, arguably better than Americans.  There are cases of libel laws used to silence journalists and bloggers, but they usually come from corrupt lower officials, mostly opposition, and private citizens.  The federal government (from both parties) has been admirably tolerant of criticism (and the main media have used and abused that freedom against Lula and Dilma). 

In fact, most of my public testimonials and press interviews about electronic voting have been criticism of the equipment which is the joy and pride of  the Electoral Justice,  whose president is a Supreme Court judge; and the criticism basically implies that the Electoral Justice is incompentent if or worse.   And in my tweets I have often and harshly critized both the São Paulo education secretariat,  the Federal education minister (now Dilma's Chief of Staff) and several other ministries, the Supreme Court and the Judiciary in general, and several other miscellaneous authorities.   I have been mostly ignored, of course, but I never felt any pressure to shut up; and ditto for uncountable other critics.  (Hm, after writing this list I am now starting to worry...  )