New Yorker William Quinn has been charged with hacking into computers owned by Verizon Communications.
Quinn, who used the name "decoder," is accused of obtaining passwords to Verizon's Direct Access Testing Units (DATU) - computers that technicians use to disable Verizon telephone numbers while performing tests on a phone line.
Prosecutors allege that Quinn used the passwords between January and April to break into Verizon's system at least 100 times, allowing him to test and disable phone numbers within various area codes across the country.
Prosecutors also claim that Quinn posted the passwords for Verizon DATUs, along with instructions on how to use them to break into Verizon's computers, on websites devoted to "phreaking", which is the practice of hacking into telephone company systems.
Verizon spent $120,000 (£64,800) to restore security, which included changing the telephone numbers for each of its DATUs nationwide and paying employees overtime to reprogram the multi-digit passwords for each of those DATUs.
If convicted, Quinn faces up to five years in prison and a maximum fine of $250,000.
Linda Rosencrance writes for Computerworld