Last week, a single tweet from the Antarctic gained 9 thousand retweets in just a few days. Data scientist Linda Zunas organised an Antarctica march on Saturday 21 January as part of the global Women’s March.

Zunas’ tweet shows a photo of her colleagues on board their expedition ship, preparing for the march.  Each of them holds a placard with a message: “Men for the earth”, “Save the planet”, “Seals for science” or “Penguins for peace”.

Zunas’ photo neatly sums up the diversity of voices that the Women’s March came to represent. It was a phenomenal protest, spreading across 7 continents and attracting more than 2 million people (some estimates say 4.8 million). And it was all started by an Hawaiian grandmother who posted an idea on Facebook back in November 2016.

Placards act like speech bubbles on social media. And they’ve come a long way since Gillian Wearing’s 1992-3 photo series Signs that say what you want them to say and not signs that say what someone else wants you to say. Pre-dating social media by a good decade, Wearing’s collection was prescient. She saw the need for personal expression in a world full of broadcast marketing and communications messages.

There were quite a few “Resistance” placards and banners on the Women’s March in London last Saturday. And #resistance is trending on social media with at least one dedicated YouTube channel and a number of rogue Twitter accounts dedicated to telling the truth while official channels are hit by censorship.

Much has been written about fake news and search engine manipulation by alt-right groups. Now it’s the turn for everyone else to get their act together.

What’s your cause? What’s your thing worth fighting for? Whether it’s Star Wars or abortion, that doesn’t seem to matter, now’s the time for marching. Because so many of the things that we seem to have taken for granted are at risk of being taken away.