Or when the Irish elected Sinn Féin MPs to parliament and the voices of the MPs were banned from the BBC.

That wasn't BBC specific - it was a law for all UK media

https://en.wikipedia.org/wiki/1988%E2%80%931994_British_broa...

Those Sinn Fein MPs also happened to occupy leadership positions in the IRA, a proscribed terrorist organisation responsible for assassinating several MPs, launching mortar attacks against Downing Street, blowing up a hotel the PM was staying in, and murdering numerous civilians in indiscriminate bombings.

I would recommend you search for "Military Reaction Force" - the terrorism started with the British Army.