The suspected leader of a hacking ring has pleaded guilty to carrying out attacks on several companies. Hector Xavier Monsegur of 'Lulzsec' had been charged with conspiracy to engage in computer hacking, according to unsealed court papers. News agency sources suggest that the suspect had co-operated with the US government. Computing expert, Professor Alan Woodward, commented that Lulzsec had been quiet since the middle of 2011 following a well-documented attack on money handling organisation Paypal.