Sadly it’s merely an “apparently” at the moment, sorry - and only based on a handful of other people having said so. I’d be interested in seeing any newer concrete sources myself to be honest.

I’ve had a quick look around, and there’s some older ones below, but it kind of sounded like something more recent - as I’ve heard several unrelated people kicking off about it in the last month.

independent.co.uk - How your entire identity could be sold for £30 on the dark web This is mostly talking about Discord-era stuff, and is from January.

Malware Bytes - 153M+ driver’s licenses for sale on new dark web platform This one is recent, but based on American data - so not directly connected to the “Online Safety Act”, other than a warning.

Daily sceptic - They Said it Was to Protect Kids. Now Your Passport’s on the Dark Web – and Your NHS Record is Next This is basically a year old - and again is mentioning the discord stuff.

parliament.uk - The Online Safety Act: implementation and impact This is official government paperwork about the OSA being shit, but doesn’t mention any specific incident - I wonder if there’s an article connected to this which discusses it?

Metro - Hackers sell scans of 153,000,000 US driving licences – and drivers here could be next This is recent, and in a very widespread UK newspaper, but is covering a recent US related incident. I wonder if this is the source of hearing a lot of very separate people talking about it recently?

Anyway, sorry I can’t find more about it (yet!).