No one stopped this museum visitor from removing a painting from the wall and walking out with it

Russia's Ministry of Internal Affairs reported that a museum visitor walked out of Moscow's Tretyakov gallery with a painting worth $1 million tucked under his arm. As you can see in the video above, visitors in the crowded gallery watch the man as he removes the painting from the wall and walks out with it, but no one stops him.
The suspect has since been apprehended and the painting, Ai Petri.Crimea by Arkhip Kuindzhi, recovered.
Image: Russia's Ministry of Internal Affairs/YouTube