(ShareCast News) - A second teenager has been arrested on suspicion of hacking the details of over 4m TalkTalk customers.Metropolitan Police said a 16-year old boy was arrested on Thursday in Feltham, West London and released on bail to appear before magistrates at a later date.Police also confirmed that a search was carried out a residential address in Liverpool.Earlier this week, police in Northern Ireland arrested a 15-year old boy from County Antrim on suspicion of offences under the Computer Misuse Act. He was released on bail until November.TalkTalk announced last Friday that a criminal investigation had been launched by the Metropolitan Police's cyber crime unit following a "significant and sustained" cyber attack on the company's website.TalkTalk has since insisted that criminals would need more information in order to take money from customers' bank accounts and said the chance of thieves succeeding with this was "very small'.