Who hacked M&S?

How much do you think your personal information is worth to criminal gangs?

Millions of customers details were stolen when Marks and Spencer was hacked in April, bringing much of its online business to a standstill for weeks.

So how much damage has it done and who are DragonForce, the group the Marks and Spencer chairman said is believed to be behind it? 

Consumer Editor Chris Choi tells Lucy Watson What You Need To Know.