This week, the United States Securities and Exchange Commission (SEC) suffered an embarrassing—and market-moving—breach in which a hacker gained access to its X social media account and published fake information about a highly anticipated SEC announcement related to bitcoin. The agency regained control of its account and deleted the post in under an hour, but the situation is troubling, especially given that the prominent and well-respected security firm Mandiant, which is owned by Google, had its X account compromised in a similar incident last week.

Details are still emerging about exactly what happened in each case, but there are common threads that made the account takeovers possible—and there are ways to protect yourself.

Crucially, both accounts had the digital protection known as “two-factor authentication” disabled at the time of the takeovers. Also known as 2FA, the defense requires a rotating numeric code or physical dongle in addition to a person’s login credentials, so everything isn’t resting on just a username and password. The SEC has not yet said whether it had two-factor turned off accidentally as a result of X’s February 2023 policy change, which made it so only accounts paying for a Blue subscription would have access to two-factor codes sent via text message. Mandiant implied on Wednesday that this change was the reason it did not have the protection turned on for its X account, saying, “Normally, 2FA would have mitigated this, but due to some team transitions and a change in X’s 2FA policy, we were not adequately protected.”

Mandiant said hackers were able to guess the password protecting its X account in “a brute force” attack. X itself said on Tuesday that the SEC account hack was the result of “an unidentified individual obtaining control over a phone number associated with the @SECGov account through a third party.”

The two incidents lay out a punch list of the most important steps you can take to lock down your X account. First, ensure that your account is protected by a strong, unique password. Second, turn on two-factor for your account or, if you think you already have it on, check to make sure. X’s move to make people pay for a…