Well-meaning though it may be, London Underground users hate the idea.
The mysterious campaign emerged on social media this morning - although the majority of images seemed to be from the campaign's Facebook page, suggesting few badges had actually been handed out.
All we know is that the badges (if they actually exist) bear a remarkable similarity to Transport for London's (TfL) "Baby on Board" badges, but bear the legend "Tube chat?".
They come attached to a flyer explaining: "Have a chat with your fellow travellers. Wear this badge to let others know you're interested. You'll benefit from a daily chat. Start using it today!".
The one thing we do know is that neither City Hall nor TfL are behind the campaign.
A spokesman for TfL said: “This is not an official Transport for London campaign. We currently only promote two badges to be worn while travelling – our ‘Baby on Board’ badge and a new trial badge for people with hidden disabilities which encourages passengers to offer those less able to stand a seat.”
You might also like: How to make Tube commuting a happier experience
Londoners' reactions - on social media, naturally - were, for the large part, horrified and appalled in equal measure
Some just took issue with the grammar
... although some were more embracing of the concept
... and some chose to see the bright side
I'm glad about the #tube_chat badge because me not wearing one will surely indicate that I am fully off-limits re: unwarranted mouth-noise.— patrick (@marginalgloss) September 29, 2016