From March this year all ISPs will by law have to keep information about every e-mail sent or received in the UK for a year. Currently many do this on a voluntary basis but this will now become mandatory. With little evidence to support their position, the government says this move is vital for monitoring crime and combating terrorist activity. The new rules are due to come into force on 15 March, as part of a European Commission directive which could affect every ISP in the country. It will cost between £25m and £70m. The rules already apply to telephone companies, which routinely hold much of the data for billing. The Home Office think the data is vital for investigation and intelligence gathering.