The price of free speech - and censorship

America was built on the premise of free speech, but today's news is filled with examples of limiting people's expression – from prohibitions against misinformation, to book bans and state laws restricting how teachers can discuss such topics as racial injustice, sexual orientation, and gender identity. Correspondent David Pogue talks with writers and academics about free speech and a corresponding climate of self-censorship; and with a New Hampshire history teacher who says, "The ghost of Senator McCarthy is alive and well in some of our state house hallways."