You know that AI that triggers Barclays (and other banks) to put a stop on your card because they think a transaction is likely to be fraudulent? Useful there, albeit occasionally inconvenient. Also automatically puts purchases into particular categories to 'help with budgeting' and triggers more targeted marketing.
Few tweaks and it monitors what you are buying. Like men's socks, a man's jumper, maybe some non feminine toiletries like razor blades or non floral shower gel - oh, your benefit has been stopped because we have evidence there is a partner living with you.
Your card was used five times in Swanage when you live in Staines, your benefit has been stopped because you're on holiday when you should be a) looking for work b) you aren't supposed to be able to travel and c) One of your purchases 2 years ago was in Mountain Warehouse for walking boots and one last month was for ski socks, so you must be planning to walk the Southwest Coast Path, not going to your cousin's funeral.
Of course, it will also pick up on older people living abroad but coming back for NHS care - they've used their card in Spain for 9 months, so the AI automatically flags them up as not resident in the UK.
Doesn't take much thought to realise that this will be incredibly easy to have running away in the background with extremely limited human involvement.
Data is fascinating. But has no ethical or moral stance - that's the preserve of the humans wanting to harness it and is by no means guaranteed. It can facilitate great good and great harms, depending upon the motivations of the humans behind it.