Freedom of Speech is when I say whatever I like without consequence, including criticism.
Oppression of my Freedom of Speech is the moment you open your mouth to criticism any of my views.
Hence Duck Dynasty can be a freedom of speech issue, whilst Anita Sarkeesian is censorship.
Although, tangentially, I'm not all that sure about Freedom of Speech. It's meant to support unpopular opinions, in times where opinions or information was needed, but unpopular, such as views critical of the government, or society, that needed changing. But now, just lump in a bunch of NDA bullshit, and governments and corporate entities can potentially ruin you for speaking out. When actual whistleblowers uncover wrongdoing, like Snowden or Assange, they're hunted. It's questionable whether they had the right to release the information they did, or even possess it, but it's also questionable why illegal doings, or simply wrongdoings were covered up(Were a private individual to do that, it would be very illegal). Instead, "Freedom of Speech" tends to get invoked to protect bigots saying that gays should die, women should be raped, and other bullshit hate speech. And a lot of that shit's intensely harmful. I really couldn't give a shit if racists couldn't say "******" or homophobes "******". I really couldn't give a shit if those misogynists who threaten rape were imprisoned for their threats. If protecting the innocent from their bullshit means reigning in their freedoms, then yeah, I'm all for it. The freedoms of those innocent of wrongdoing are more important than those of bigots. Free Speech tends to only be invoked for evil shit, and rarely improves the morality of society, or keeps government in check.