After WikiLeaks was blamed for sharing classified information that the US government didn't like at all, the US Government illegally forced payment processors including Visa, Mastercard, PayPal and other to block payments to them.
Come 2011 June, when they started accepting Bitcoin donations.
In fact, they wanted to do so earlier, but Satoshi himself asked Julian Assange not to turn to Bitcoin, because he thought that since it was in its early stages, the government interest in Bitcoin would bring unnecessary trouble for them.
Here's what Satoshi had to say about it:
“The project needs to grow gradually so the software can be strengthened along the way. I make this appeal to WikiLeaks not to try to use bitcoin. Bitcoin is a small beta community in its infancy. You would not stand to get more than pocket change, and the heat you would bring would likely destroy us at this stage.”
Julian Assange agreed with this, and decided to wait it out.
Half a year later, in June of 2011, they started to accept Bitcoin, and saw 50,000% increase only in 6 years, after being forced to hold Bitcoin.
People always ask what usecases Bitcoin has, but what better example of it than this?