Canadian singer Justin Bieber poses with a pot of ice water in a video posted on his Instagram account.

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The challenge involves people getting covered with buckets of ice water on video, posting those videos on social media and then nominating others to do the same, all in an effort to raise public awareness on ALS. Those who refuse to take the challenge are asked to make a donation to the ALS charity of their choice.

Bieber, who has recently pleaded guilty to careless driving and resisting arrest, took on the challenge and doused himself with a bucket of icy water. Who is his nomination? President Barack Obama.

The singer's philanthropic act may win him some thumbs-ups after brushes with the law so many times in the past. Whether the US President would take the challenge remains a question.

Amyotrophic lateral sclerosis, also referred to as motor neuron disease, is a neurodegenerative disease characterized by muscle plasticity, rapidly progressive weaknesses and difficulty in speaking, swallowing and breathing.

Symptoms are often related to malfunctions of the muscles. In severe cases, serious muscle inaction may cause the patient's body to go into a "frozen" stage, a phenomenon that's imitated by the Ice Bucket Challenge through pouring ice water on one's body.