Since Friday, 24 July, it is now compulsory to wear face coverings in England while on public transport and in shops such as supermarkets.
However, anti-mask activists have taken issue with the rules, arguing that they have a right to choose not to wear a mask, despite the fact that doing so will help to prevent the transmission of Covid-19.
Last week, protests erupted in London as 100 or so people who gathered in Hyde Park as organised by the group Keep Britain Free.
Clare Wills-Harrison, one of those organising the event, said the demonstrators were "campaigning for the return of our rights and liberties".
The protests have continued on social media, with people sharing selfies of themselves not wearing masks under the hashtag #NoMaskSelfie.
— Charlotte (@beanjellybean76)July 24, 2020
Now, however, the hashtag seems to be populated with photos of people wearing masks in order to stop anti-mask activists from spreading their message.
"Am I doing the #NoMaskSelfie right? I think so," tweeted one person alongside a selfie of them wearing a mask.
— Jason Harris (@LargeRugby)July 25, 2020
"This hashtag existing is why I keep it on... so many selfish and ignorant people," added another with a photo of themselves in a mask.
— Elian Williams V/A 🏴 (@elianwilliams3)July 24, 2020
You can read more about how face coverings protect you and others from contracting Covid-19 here.