About 1,800 Verizon customers received the email, which contained names, mobile numbers, device type and email addresses, according to a company statement. The email, meant to be an electronic order form, was followed by another message written to "recall" the original email.
Spokeswoman Jan Morris said in an email today that Verizon sent two emails last week to the affected customers, apologizing for the breach.
"Because Verizon Wireless takes the security, confidentiality and integrity of our customer's personal information very seriously, we communicated with all of the roughly 5,000 customers, expressing our deep regret and advising them that we have already implemented additional quality control procedures and process improvements to prevent a reoccurrence," the statement said.
Verizon Wireless officials do not believe any of the information contained in the attachment could lead to fraudulent activity.
"It is highly unlikely that this information could be used to compromise any other account," the statement said.
But analysts said in published reports that fraudsters could use the information as a building block to obtain more confidential information, such as bank account numbers, from unsuspecting Verizon customers.
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