The ice bucket challenge is the latest example of "slacktivism" – online activism that requires minimal time, effort or meaningful involvement.

Tom Cruise has done it. So has Mark Zuckerberg. Even George W Bush has given it a bash, although it's clear from the video he's not entirely sure why.

In this latest trend, the idea is to pour a bucket of cold water containing ice cubes over your head and post the video on social media. And possibly donate money. And there you have it, you've done your bit for motor neurone disease.

It's hard to remember when there wasn't a so-called challenge to raise awareness or money for charity. There has been "no make-up selfies", various wristbands (for the fashion-conscious, such as Lance Armstrong) and innumerable other fads that disappeared as quickly as they turned up on our news feeds. And left behind are the problems they pledged to solve.

Granted, ice-bucketing has raised money for ALS Association, a charity for Amyotrophic lateral sclerosis – otherwise referred to a motor neurone disease or Lou Gehrig's disease.

The Telegraph reported on Wednesday that over £13 million has been raised so far and, unsurprisingly, the group is speechless with delight.

More than 700,000 new donors have given money to the charity – amounting to more than double the total number of contributions they received in the year ending January 2013. The money will go into research to find a cure for the debilitating disease and that can only be a good thing.

But for the countless number of celebrities that have taken part, the ice-bucketing has little to do with philanthropy. They are creating awareness – and everyone is aware of the lure of a celebrity doing something wacky – but it's essentially a wet T-shirt competition for the narcissistic, window-dressed as something charitable.

Pop it on Facebook or Twitter and you've got a platform to publically flaunt your good deed in return for shares or likes. It's an ultimately shallow exercise in raising awareness of oneself.

Justin Bieber – who last year commented that Anne Frank was a "great girl" and a "Belieber" in a museum's guestbook – posted a shirtless video of his ice bucket challenge.

He had to film two attempts because he got it wrong the first time and then nominated all his "Beliebers". Even Nicole Scherzinger took a break from orgasming over yoghurts to "show off her super-toned abs" (thank you, Daily Mirror) – all in the name of charity.

The original idea of the ice bucket challenge was to either dump water on your head or make a charitable donation. Or? Therein lies the problem.

It is easy to criticise charitable acts, but the likelihood is that the money – when the social media hype dies down in a couple of weeks – will stop flooding in. Celebrities who donated won't give the campaign another thought, if they thought about it in the first place.

Ice-bucketing has reached the point where people are arguing about which charity "owns" the phenomenon.

Macmillan Cancer Research has been criticised for hijacking the campaign – with commenters arguing it should have allowed lesser-known ALS to have its moment.

But surely this is forgetting the point of charity – it is bonkers to sit back and argue over who stole what. ALS raised money and the money donated to Macmillan funded six more specialist cancer nurses, who can support up to 1,000 patients a year.

The ice bucket challenge has raised funds and awareness for ALS and elsewhere. But it would be refreshing to see money raised is a less egotistical way – without the reward of clicks or likes.

You can donate to ALS or Macmillan here.