More publicly traded companies may disclose details of attacks from China-based hackers as they file 10-Ks in coming months after the SEC began requiring the disclosure of cyber crimes in October, Reuters reported. Companies including Google (GOOG.NASDQ), Intel Corp and Adobe Systems (ADBE.NASDAQ) have admitted to being attacked by China-based cyber spies in the past, but the total number of companies which suffer espionage is likely much higher. Mandiant Corp, a Virginia-based security firm that has responded to cyber-based incidents at 22 Fortune 100 companies, estimates that more than 20% of Fortune 500 companies have experienced serious breaches. Joel Brenner, the US counterintelligence chief until 2009, has estimated that the networks of more than 2,000 companies, research universities, internet service providers and government agencies were hit over the past decade by China-based hackers. “It doesn’t square that billions of dollars in intellectual property are being lost and investors don’t care,” said Jacob Olcott, a former staff expert on cyber security who testified before the Senate Commerce Committee.