Sunday morning viewers of a Czech public television channel saw an unexpected sight during the broadcast of the weather. The screen was showing a panning scenic shot of the Krkonose Mountains in Bohemia, as the announcer delivered the weather report. Suddenly a large mushroom cloud appeared in the distance.
Luckily the Krkonose Mountains hadn't been nuked. The scene was the work of a Czech art group calling itself ZTOHOVEN. They had managed to hack into one of the station's camera feeds, and replace the incoming video with their own content.
Czech TV isn't very happy about the prank. They're filing criminal charges against the group.
Its members also changed into a question mark the red neon heart by Jiri David that was installed at Prague Castle during the last days of Vaclav Havel's tenure as Czech president.
In 2003 they covered 800 advertising showcases in Prague's underground with white posters featuring a large black question mark and a reference to their internet pages.