Preacher v selfies, 'Frozen' parody, a lip-synch sensation: Trending's videos of the week

Here are BBC Trending's top videos from the past week - including some of the stories behind big social media trends.

Indonesia loves selfies. Even the country's president has posted them. But the self-portrait has inspired an angry debate on social media after a prominent online preacher, and member of the Islamist Hizb ut-Tahrir party, criticised them as "arrogant" and "narcissistic."

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A photo taken of a New York City student and posted onto Facebook has turned into a viral fundraising hit. Brandon Stanton, who takes street portraits and posts them on online as Humans of New York (HONY), has over 11 million Facebook fans. His photo of a boy named Vidal caught his audience's attention. People have donated hundreds of thousands of dollars to help Vidal's school in one of New York's poorest neighbourhoods.

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Schoolchildren in the north-eastern United States had a lot of time on their hands to watch YouTube videos during a snowstorm this week. A teacher's amusing way to tell students to stay home - a parody of "Let it Go" from the hit animated film Frozen - was watched thousands of times.

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A smartphone app allowing users to lip-synch over their favourite songs, speeches or film quotes and share the results online has become a massive internet hit. The "Dubsmash" app has been downloaded more than 10 million times since its launch in October, but could copyright issues cause problems for the app's young German creators?

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And also on our blog this week:

"The government invites you to be wary of those who do not eat baguettes"

What did Saudis really think of Michelle Obama NOT wearing a headscarf?

Nepalis pretend to smash furniture - it's a political protest

Why did one death out of many go viral in Egypt?