Federal regulators are accusing Sprint of illegally billing its wireless customers tens of millions of dollars in unwanted charges for text message alerts and other services. The Consumer Financial Protection Bureau says it has sued the telecom company over billing for unauthorized charges, a practice known as 'cramming.' The agency said Sprint failed to oversee third-party companies, allowing illegal charges to be put on customers' bills. The bureau said the charges ranged from one-time fees of 99 cents to $4.99, to monthly subscriptions costing $9.99 a month. It said Sprint received up to 40% of the revenue from the charges. The Federal Communications Commission is expected to fine Sprint a record $105 million for the alleged violations - that's according to The Wall Street Journal.