Internet giant Yahoo has revealed more than one billion user accounts may be affected by a hacking attack. This marks the biggest cyber hack to date, with the attack dating back to 2013. It’s separate from a data loss in 2014 when 500 million accounts were accessed. The news comes at a critical juncture for Yahoo, who is trying to sell its core businesses to the telecoms and media company Verizon. Matt Cox spoke to Peter Church, Counsel specialising in data privacy at law firm Linklaters, to find out the consequences.