To assist class action defense attorneys anticipate the types of cases against which they will have to defend in California, we provide weekly, unofficial summaries of the legal categories for new class action lawsuits filed in California state and federal courts in the Los Angeles, San Francisco, San Jose, Sacramento, San Diego, San Mateo, Oakland/Alameda and Orange County areas. We include only those categories that include 10% or more of the class action filings during the relevant timeframe. This report covers the time period from September 17 - 23, 2010, during which time an unusually low number of new class actions -- only 36 -- were filed in these California state and federal courts. Labor law class actions generally top this list, often account for more than half of all new class actions filed in these courts. This past week, however, only 12 new labor law class actions were filed, representing a relatively low 33% of the total number of new class actions filed. The only other categories to break the 10% threshold involved claims under California's Unfair Competition Law (UCL), which includes false advertising claims, with 7 new filings (representing 19% of the total number of new class actions filed), and alleged violations of federal securities laws, with 6 new filings (representing 17% of the total number of new class actions filed).