About 90,000 people signed a petition calling for the pro-badger cull Glastonbury boss to leave.
Several police cars and ambulances are on Albemarle Street in central London.
Chief Constable Olivia Pinkney apologised for the force’s “part in the distress caused to families”.
The man is warned by police after sending threats to the chairman of Scotland Natural Heritage.
Some of the more unusual ways people across England marked the longest day of the year.