AT&T (NYSE: T) and T-Mobile USA have been banned from saying their voicemail systems are secure after agreeing to a settlement in a Los Angeles county court, PC World reports. “Cellphones purchased by undercover investigators were easily hacked into, enabling the voicemail to be changed at will,” the Los Angeles District Attorney’s Office wrote in a statement. “Hacking into voicemail allowed messages to be changed or erased. Important information could be removed from the voicemail and phony information could be inserted.” The investigators used SpoofCard software to display other numbers on caller ID and gained access to the carrier’s voicemail systems since they don’t require passwords. AT&T was fined $59,300 in penalties and T-Mobile will pay $25,000.