Google is cracking down on Gmail users who use their personal accounts to send email to other users, in what it calls a “hack” to protect users from identity theft.

The company says it’s doing so in response to a growing number of cyberattacks, particularly attacks against businesses and government organizations.

In a blog post, Google said it blocked access to its Gmail service to the following accounts: those that used their Google account to send emails to Gmail accounts owned by others; those that were used to send an email to another person’s Gmail account; those whose email addresses matched a Gmail user account.

Google has been aggressively cracking down in recent months on the use of phishing scams to steal information and access accounts, as well as on cyberattacks on government and corporate networks.

In December, Google announced plans to introduce a new tool called a phishing-and-malware filter that would block phishing and malware attacks and help protect users against identity theft by giving them the option to opt out of sending emails to any account.

But Google said Friday that it is now banning Gmail accounts from sending email to accounts that are owned by other users and is limiting access to those accounts to a single Google account.

The move is the latest sign that Google is working to prevent identity theft attacks, said Brian Krebs, the founder of, who has written about the rise of phish scams.

The new ban will also block users who have previously used Google email addresses to send Gmail emails.

Google said the new ban does not apply to Google+ accounts.

It is not clear whether Gmail accounts will be automatically blocked when a user’s Gmail password is changed, and if they will be allowed to use their Google+ account to log in again after the new policy takes effect.

The blog post did not say what happens to the accounts that Google has blocked in the past.

Google did not immediately respond to a request for comment.

In October, Google blocked access for one of the biggest accounts in Gmail: Google+ users.

That ban has been in place for years, but only temporarily.

Google+ is Google’s popular social network for its users to post and discuss anything related to their Google business.

It has become a target of hackers and hackers have been exploiting it for malware attacks, and hackers in the U.S. and Europe have been trying to steal passwords from Gmail accounts.

The latest round of phishes was detected at Google’s headquarters in San Francisco in December, said Mark Thompson, a Google security engineer.

He said Google has taken steps to block the phishing attack by blocking accounts from being able to send or receive Gmail messages.

“We’ve also worked to block people from sending Gmail to any Google account they are not authorized to send to,” he said.

Google added that it has blocked accounts from sharing Gmail passwords.

Google is also cracking down hard on phishing attacks by phishing emails with malware or phishing websites that look like legitimate Gmail accounts to trick users into clicking on links or clicking on advertisements that then appear on a website.

Google blocked the following phishing sites: karaoke phishing site, karaokeshoes phishing website, phishing,

Google also blocked a number of malware websites, including the malicious site called

Google will not say whether the bans will continue for accounts owned in part by other Google users, and whether the new restrictions will affect all Gmail accounts, including those owned by individuals.