On image sharing website Instagram there have been 3.7 million videos uploaded with the hashtags #ALSicebucketchallenge and #icebucketchallenge. Justin Bieber's has been the most popular - with about one million "likes".
The stunt is typically intended to raise money and awareness for the Amyotrophic Lateral Sclerosis (ALS) Association. Its British equivalent, the Motor Neurone Disease Association, has also benefited.
From 29 July to 28 August this year ALS received $98.2m - compared with $2.7m donated during the same period last year.
Pre-ice bucket, the MND Association would receive on average £200,000 a week in donations. From 22 to 29 August, it received £2.7m.
In the UK, other charities have benefited with Macmillan Cancer Support raising £3m from challenges. Water Aid has seen a spike in donations, including £47,000 in one day - 50% higher than it ever received in a single day before. The money came in part from people bemoaning the water wasted in the challenges."