> "There exist things such as 'harmful ideas'"

The irony of the above being that we only got to where we are today because people were willing to advocate ideas that were universally considered "harmful ideas" like the abolition of the divine right of kings, freedom of religion, equality of all races, and equality of the sexes.

What view considered "harmful" today will spawn the next protected class of tomorrow? If we listen to the parent poster, we will never know.

who gets to decide which ideas or not debatable?

Thanks for the video link.