Zainab Hakim finds it tiring to go to the shops but thinks she might be addicted to shopping. She’s a 23-year-old receptionist from Birmingham, and doesn’t visit the high street to buy clothes – she watches sellers livestream on the social media site TikTok, peddling their wares in real time. With a couple of clicks, she can buy things via the app. “I probably have an addiction at this point,” she says. “I just get sucked in.” At any time of day, you can scroll through TikTok Live and see someone selling all sorts of things – from clothes to...