Time Warner Cable is warning that login credentials for 320,000 customers may have been stolen. The TV cable and Internet service provider told Reuters that e-mail passwords may have been harvested by malware installed on customers' computers or that the potentially compromised passcodes may have been the result of data breaches of other companies that stored Time Warner Cable customer information. The company is still investigating how the data was obtained, but so far has found no indications that its systems were breached.

A Time Warner spokesman told the news agency that the company issued the warning after receiving notification from the FBI that some customer e-mail addresses and passwords "may have been compromised." As a precaution, company officials are sending e-mails and direct mail correspondence advising customers to update their passwords.

The Time Warner advisory comes a day after Web host provider Linode said it was resetting user passwords following signs of a breach. The reset came after an investigation of "the unauthorized login of three accounts [that] has led us to the discovery of two Linode.com user credentials on an external machine. This implies user credentials could have been read from our database, either offline or on, at some point." The database contains usernames, e-mail addresses, "securely hashed" passwords, and encrypted two-factor seeds.

The Linode advisory also said company officials have been actively fighting distributed denial-of-service attacks.