Google is profiting from millions of typo-squatting websites that earn advertising from Google's Adsense advertising program, Harvard University professor Ben Edelman says. In a report published Monday, Edelman says Google profits from typo-squatting websites that run ads using Google's Adsense — which, ironically, are often bought by the owners of the legitimate sites web surfers were trying to visit. Typo-squatting sites are found at domains that have one letter different from legitimate, trademarked domains — bankofdamerica.com, for instance, as depicted in the screenshot above, which has a "d" in the URL. Typo-squatting has been around since the beginning of the web, but until recently, typo-squatters had limited means of profiting from surfers' bad spelling or clumsy typing. But using Google's Adsense for Domains (AFD) program, typo-squatters fill their sites with sponsored links that often point to the legitimate domain. If a misdirected surfer hits a sponsored link, the legitimate domain owner ends up paying the typo-squatter for that referral, and Google as well. Edelman and other lawyers have filed a class action lawsuit representing domain owners who claim the Google Adsense for Domains (AFD) program is assisting in violating trademarks. A hearing is scheduled for as early as next month in which Edelman will ask an Illinois federal judge to allow the case against Google to proceed.