When Belgian police asked witnesses not to tweet officers' movements during raids targeting terrorism suspects across the country's capital, the Internet reacted in perhaps the only way it knows how: with cats.
Heeding Defense Minister Steven Vandeput's call, Belgians — and then seemingly the rest of the world — seized the #BrusselsLockdown hashtag to post jovial photos of feline friends on Sunday.
While ostensibly frivolous, the viral meme's effect was threefold. It enforced the Twitter radio silence, buried any tweets that might harm the operations, and eased some of the tension in what has become an anxious city.
It also proved that if the Internet is provided with a vacuum, its inhabitants will fill that vacuum with cats.
By Monday morning, the hashtag had been used around 170,000 times — with a healthy number of those tweets featuring cats in various postures of predictable cuteness and charm.
Brussels has been on lockdown since Saturday after what the country's prime minister said was the "serious and imminent" threat of a Paris-style attack.
Sixteen people were arrested in a series of raids across the city Sunday — although a fugitive wanted in connection with the massacre in Paris was not among them.
Even the Belgian police joined in, posting this message of thanks to the thousands of cat-lovers who contributed.
Their tweet read: "For the cats who helped us last night ... Help yourself!"