In August 2014, a flash mob appeared on the internet whose goal was to raise donations to fight the still-incurable disease ALS, Amyotrophic lateral sclerosis. The flash mob works according to the following algorithm: one person accepts a challenge (passes the baton) from one person, nominates the next three, makes a donation, and pours a bucket of cold water over themselves.

Here’s Mark Zuckerberg, founder and CEO of Facebook, accepting the challenge from the governor of California and passing it on to Bill Gates:

And here’s Bill Gates accepting Zuckerberg’s challenge:

This unconventional approach, of course, went viral. Videos of people dousing themselves with cold water are racking up tens of millions of views.

Sunday evening was quiet and gave no sign of trouble. But then the iPhone made the push-notification sound. I open Instagram, and theere, and theeeere...

Kristina, I gladly accept your challenge and want to pass it on to three good friends of mine: Dima Melnik, Taras Filatov, and Olga Sinelnikova. You have 24 hours to accept my challenge! :)

And a brief FAQ:

— Is this mandatory?
— No, it’s not mandatory; it’s all voluntary.

— Where do I send the money?
— You can send it to ALS (http://www.alsa.org/fight-als/ice-bucket-challenge.html), or to any other organization for any other cause.

— Does it have to be 10 or 100 dollars?
— Any amount will be welcome anywhere.