Social media has become an easy and effective way for corporations and public figures to reach large audiences quickly. But a recent account hijack renews concern about cybersecurity—especially when it comes to a well known corporate CEO being impersonated.

Fast Company reported earlier this week that the Twitter account of publisher Pantheon Books was hacked overnight. As Fast Company wrote, this cyber attack was particularly concerning for two reasons: “One, the hackers were able to impersonate Elon Musk—right down to his familiar Twitter profile picture. And two, Pantheon is a verified Twitter account with a blue checkmark.” The goal of the account takeover was to scam followers into sending the hacker bitcoin.

Claiming to be Tesla CEO Elon Musk and featuring the same profile picture that Musk actually uses, the hacked account announced a bitcoin offering: Send 0.1 to 2 bitcoin to a designated wallet and the user would be automatically ‘entered’ into a giveaway of 10,000 bitcoin.

With the hacker able to change the account’s name and picture to a popular figure, and actively promote a known bitcoin giveaway scam, the reliability and security of Twitter’s ad system is again thrown into question—especially since the issue wasn’t caught for several hours. Adding salt to the wound, the hacker also promoted the tweet.

The incident comes not long after the Facebook data breach, re-stoking concern about the vulnerabilities of social media platforms. Just a few months ago a widespread cyber attack impacted hundreds of users on Instagram, another popular social media platform. Similar to the Twitter hack, accounts were taken over—in that case by what seemed to be Russian hackers.

These cybersecurity incidents are a reminder that there’s still plenty of work to be done to ensure safe user experiences. The risks for those with high-profile accounts is not insignificant—especially given that it’s not uncommon for major brands and top-level executives to have a presence on social media platforms like Twitter.

Get the full story at Fast Company.