Considering the explosion of layoffs announced in recent weeks, companies would do well to seriously be on guard against data theft. According to a survey that polled some 800 companies in eight countries, 42 percent of firms admitted that laid-off employees were the single largest threat to their data security.The survey, which was unsurprisingly conducted by security / technology firm McAfee, found that businesses overall risk losing over one trillion dollars from “loss or theft of data and other cybercrime.”