That's AI!

It begins with the realisation that a lot of images and text on social media are generated by AI.  So if you see something you don’t believe, you say ‘That’s AI’ meaning it is false because it is generated by AI.  From there the extension of use is straightforward.  Anything you don’t believe is true you call out as AI.  ‘There’s free meat pies at the canteen!’ ‘That’s AI!’

So that’s AI simply means ‘that’s not true, not genuine, not authentic’.  Online and offline. Wherever.  This is kid’s slang at the moment but the kids will grow up and entrench it in the language.  Commentators note that it is a pleasing break from That’s cap! which was the expression of disbelief that preceded it. That one comes from Black American English, from the capping game in which people trade insults, each one trying to cap what went before.  The winner is the person who stays cool. Cap extends to anything exaggerated beyond belief.