Hackers stealing trade secrets on industrial scale, warns spy chief Russia and China are regularly accused of being behind many state cyber attacks although the UK spy agencies never say who they suspect. The head of cyber at MI5 said: "There are now three certainties in life, there's death, there's taxes and there's a foreign intelligence service on your system. There are hostile foreign states out there who are interested in a company's mergers and acquisitions activity, their joint venture intentions, their strategic direction over the next few years and that information would be valuable to that country's state owned enterprises. Sir Iain spoke to the programme before the allegations emerged from the CIA whistleblower Edward Snowden that GCHQ had benefited from the US Prism snooping programme. The spy chief later insisted his organisation operates at all times within the law and statutory safeguards required of it. It came as a parliament watchdog revealed a planned public evidence session with the heads of the security and intelligence agencies has been postponed. The Intelligence and Security Committee said it needed the delay to focus more on investigating the allegations against GCHQ as well as the fall out surrounding MI5 following the alleged murder of soldier Lee Rigby. The first ever public hearing was due to be held this month but will now be staged in September. A committee spokesman said: "The Intelligence and Security Committee had intended to hold its first open evidence session in July. However the Committee is currently investigating both the murder of Drummer Lee Rigby and the allegations surrounding GCHQ as a result of material leaked by Edward Snowden, and these Inquiries must take precedence. The open evidence session has therefore been postponed until after the summer recess.