McAfee surveyed 600 IT security executives and found that over half of them had already suffered large-scale attacks from organised criminals, terrorists, or nation-states.

A number of Congressional websites were defaced with rude messages aimed at President Obama after the State of the union address on Wednesday.

Facebook users were plagued with an unnamed application that people thought was a piece of malware before realizing that it was simply a user interface bug. This was rapidly succeeded by a real-life worm that rapidly replicated itself through selective accounts on the social networking site.

A laptop stolen from the Methodist Hospital in Houston, Texas, contained the personal records of 689 people. The machine, which was stolen on January 18, contained private health information and Social Security numbers, according to reports.

While some focused on stealing data directly from back end databases, others were caught trying to target ATMs. Jean-Pierre Griffin and an unidentified man were caught putting skimmers on an ATM machine near the University of St Thomas in Houston.

UK turf accountant Ladbrokes reported that an individual had passed certain details from its customer database to reporters at the Mail on Sunday newspaper.

Such data breaches are becoming more costly for organisations. The cost of a data breach increased for the fifth year running, according to an annual study released by the Ponemon Institute. Data breaches now cost $204 per compromised record, it says.

Google didn't endear itself to privacy advocates last week. The company finally updated its browser toolbar after it was caught tracking the URLs that users visited, even after it was supposed to be turned off.