It's unclear how many consumers have claims that haven't been arbitrated and could end up in court if Brown signs the measure. A Wells Fargo spokeswoman, Erika Reynoso, declined to comment. Business groups opposed the legislation, warning that the wording is confusing, likely pre-empted by federal law and could subject employers to costly and unnecessary lawsuits. "Ambiguity, inconsistency and confusion only serves to benefit trial attorneys and their ability to pursue more costly litigation with higher attorney fee recoveries, not consumers," the California Chamber of Commerce wrote in a letter to lawmakers urging them to vote against the measure. Consumer advocates oppose the growing use of mandatory arbitration in the fine print of contracts. They say arbitrators are often friendly to the corporations that hire them in hopes of getting more business settling disputes with the company. Wells Fargo says 3.5 million accounts were potentially opened without permission from customers between 2009 and 2016.