Image caption Thousands have changed their profile picture to a black square

Many people in the Netherlands have changed their social media profile picture to a black square and are using the hashtag #BringThemHome.

Right across Facebook, Twitter, and Instagram, people have swapped their standard - often smiling - profile image to a black square. One-hundred-and ninety-three Dutch people were among the 298 people on board the Malaysia Airlines flight MH17 when it crashed in Ukraine on Thursday. Many in the Netherlands are combining the gesture with a call for their fellow citizens' bodies to be repatriated as soon as possible.

The trend seems to have started on Facebook. The Foreign Minister Frans Timmermans was among the first to change his cover image on Facebook to a black background. Many friends and relatives changed their avatar to a black square.

The trend spread to Twitter and here it began to be used in combination with the hashtag #BringThemHome, which has been tweeted more than 7,000 times since the crash. "Last night, there was a big snowball effect where everybody started to put their avatar on black to express their grief," says Remco Janssen, a Dutch social media expert based in Amsterdam. Many feel the government in the Netherlands is not doing enough to get them back, he says.

Image copyright Instagram Image caption A black ribbon is also being used by some on Instagram and elsewhere

The hashtag has also been used in Australia, Canada, the UK and the US - all countries which lost citizens in the crash. In Australia, many shared the front page of the Sunday Times which ran with the headline "Bring Them Home".

But the hashtag is most widespread in the Netherlands, with its relatively small population of 16 million. "If you do the math, and six degrees of separation, everybody knows somebody who knows at least one person who was in the crash," says Janssen. "We all know somebody who was on the plane. So it's really heartfelt. Some people even said that this was our 9/11."

It's quite common for people to change their social media avatars to raise the profile of a cause, or to express grief. After Typhoon Haiyan, for example, many in the Philippines, changed their profile pictures to a black map of the country.

Janssen says he doesn't expect the hashtag, or the black avatars, to have much concrete effect. But he does believe that social media can help, in its own way, at a time like this. "Social media is like the village square... I think it has a big psychological effect on everybody to have this place to discuss - it feels like a place where everybody has a sense of joint grief."

Reporting by Cordelia Hebblethwaite

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