Why was Parsons being arrested?

Parsons was arrested for thoughtcrime. He was turned in by his daughter, after she heard him talking in his sleep.

‘It was my little daughter,’ said Parsons with a sort of doleful pride. ‘She listened at the keyhole. Heard what I was saying, and nipped off to the patrols the very next day. Pretty smart for a nipper of seven, eh? I don’t bear her any grudge for it. In fact I’m proud of her. It shows I brought her up in the right spirit, anyway.’