Attackers recently targeted science journal, and gained access to stored user login credentials, a spokeswoman for the parent company, Nature Publishing Group told

How many victims? Less than 1 percent of users were affected -- approximately 21,000 out of 2.1 million.

What type of personal information? Name, username (which is email address) and password.

Details: “The breach occurred because someone added some code into a URL and tried to bring the site down,” the spokeswoman said.

Passwords are stored in an encrypted form, so the company reset them as a precaution.

What was the response? The company has taken steps to mitigate the vulnerability that lead to this attack and is monitoring for any further attempts to access data.