Just more than a week after Twitter introduced two-step verification, LinkedIn has followed suit. LinkedIn announced in a blog post Friday that users on the social network for professionals now have the option to enable two-step verification via SMS text message to protect their accounts. “All LinkedIn accounts are already protected by a series of automatic checks that are designed to thwart unauthorized sign-in attempts,” the company said in the blog post. “Now, we are introducing a new optional feature that adds another layer of security to your LinkedIn sign-in: two-step verification.” LinkedIn suffered from a massive hacking attack a year ago, in which a Russian hacker stole more than 6 million encrypted passwords. More recently, several prominent accounts have been hacked on Twitter, including The Associated Press and The Onion.