A good definition for courage: Living in Russia and trolling Putin.

Still, that's the life of Alexei Navalny, a Russian political activist and humorist who spares no effort in illuminating the corrupted riches of Russian President Vladimir Putin and the Kremlin elite.

On Wednesday, Navalny released his latest YouTube video. In it, he uses a drone to record a rural mansion near St. Petersburg. And according to Navalny, the residence, located on a pristine island, is owned by none other than the Russian president. In Navalny's video, we see a luxurious billionaire-style retreat, replete with a helipad and other high-end amenities.

And that matters, because while Putin is notoriously unamused by claims that he misuses state finances to benefit himself, that's exactly what he does.

The Russian leader is believed to own tens of billions of dollars in hidden assets, concealed under the name of various front companies and individuals. This nest egg is Putin's insurance policy for a luxurious lifestyle should he ever chose to leave office or spend more time relaxing.

Unfortunately, Navalny's work isn't all fun and games. By bringing attention to the secret of life of Putin, the activist is under increasing pressure from various elements of the Russian state. Some of this pressure takes the form of threats and attacks, some in formal proceedings by the Russian judiciary. Regardless, the sustaining message is the same: "Shut up."

Knowing this, and that Putin's regime has no qualms about using murder as a political tool, Navalny's courage is all the more remarkable. Russian political society is defined by kleptocrats and corruption, but most Russians simply stay quiet.

That makes Navalny's work, smiling but serious, very precious. You can watch his new video here.