Brussels has been on high alert since Saturday. Underground trains aren't running, large meetings have been canceled, and citizens are being encouraged to remain at home. That means any updates on the Brussels "lockdown" are largely coming from social media, as many have turned to the #BrusselsLockdown hashtag to find out the latest about ongoing police raids and closures throughout the city.

Providing those updates are people like journalist Davide Patteri. He had his meal interrupted by police yesterday and immediately took Twitter to pass the info along.

In emergency situations, Twitter has become a primary source for of breaking news and information - particularly when tweets are coming in from people who are on location at the site of the unfolding news story. This has plenty of advantages for Twitter users. But providing information about ongoing police raids can potentially tip off terror suspects as well. It can even give them the upper hand, knowing how many police are surrounding their apartment building, for example. That can place police lives in danger.

Late last evening, Belgium's minister of defense tweeted his request that Belgians refrain from tweeting sensitive police information.

Shortly thereafter, Belgium's federal police force tweeted a similar request: "For security [reasons], please respect the radio silence on social media concerning police operations throughout Brussels. Thanks."

Thousands of retweets later, the word was out.

But the problem with Twitter is that, in a free and democratic country like Belgium, you cannot just tell someone not to tweet something. They have a legal right to do so.

And so, as tweeted images of police operations continued coming in, Twitter users came up with a solution:

They bombarded the hashtag #BrusselsLockdown with copy-pasted text telling people to stop… tweeting… about… the police - until they realized that a Belgian cameraman had already come up with an even better idea.

Cats.

"Instead of tweeting about police actions in Brussels, here's a picture of our cat, Mozart," he writes.

The idea took off.

The call for cat pictures soon went international.

Late last night, even EU parliamentarian Julia Reda joined in:

As cat images poured in, it became impossible to use the hashtag #BrusselsLockdown as a means of sourcing real news information on police operations. There were just too many cats.

Many praised the Belgians for using humor to stop terror suspects from obtaining information that could potentially endanger police safety.

The campaign to kill the hashtag was a success. In spite of police raids on 19 houses, including more than 20 arrests, Twitter users could not reasonably be expected to find information on the raids using the #BrusselsLockdown hashtag.

In the early hours of Monday morning, the federal police tweeted a tongue-in-cheek "thanks" for the surprising and helpful response by the people of Belgium - and the world.

"For all the cats that helped us last evening… here you go," they write.