Second teenage boy arrested in connection with TalkTalk hack

Police arrested a second teenage boy in London on Thursday over a cyberattack on UK broadband provider TalkTalk.

TalkTalk was subject to the " significant and sustained cyberattack" last week, and warned its 4 million customers that their data may have been left exposed.

The 16-year-old from Feltham, arrested in west London on Friday, has been released on bail after his address and another address in Liverpool were searched in connection with the crime, London's Metropolitan Police said.

A first arrest connected to the crime was made on Tuesday of this week. The house of a 15-year-old boy in Northern Ireland was searched while he was taken in for questioning, before also being released on bail.

TalkTalk has been subject to three cyberattacks in the last year, revealing the extent to which hackers are pursuing companies that hold millions of people's personal data. When these attacks are successful, customers are left powerless to control who has access to personal information, such as bank account details. The companies' share prices take a major hit.

This is especially true if some of that data has not been encrypted -- as was the case in the latest TalkTalk hack. The company is keen to reassure customers that debit and credit card details have not been accessed in the attack, but has warned people to look out for any unusual activity regarding their bank accounts.

The Metropolitan Police investigation, which it launched with the help of the National Crime Agency and the Police Service of Northern Ireland's Cyber Crime Centre, is ongoing. In the meantime, TalkTalk has hired BAE Systems to undertake its own investigation and company executives will be called before British politicians to answer questions about the hack.

TalkTalk did not immediately respond to a request for comment. The company has provided guidance for those who are concerned they have been affected by the hack.