Four people including three teenagers have been arrested at addresses in the West Midlands, Staffordshire and London as part of an investigation into a trio of cyber-attacks on Marks & Spencer, Co-op and Harrods.
The National Crime Agency said two 19-year-old men, a 17-year-old boy and a 20-year-old woman had been apprehended on suspicion of breaching the Computer Misuse Act, blackmail, money laundering and joining the activities of organised crime.