When Lori Volkman got the tweet and the Facebook message from someone claiming to be CyberCaliphate, she admits to being "pretty scared at first."

"It was an emotional response ... I was shocked," said Volkman, one of five military spouses who received the messages.

"Bloody Valentine's Day," the Facebook message was titled. It read: "We know everything about you, your husband and your children and we're much closer than you can even imagine. You'll see no mercy infidel!"

Someone had hacked into the Twitter account of another spouse and sent threatening messages to that spouse, Volkman and four other military spouses through the hacked account.

"Then I realized they were only targeting people quoted in a news article" in January, after the U.S. Central Command Twitter account was hacked.

But Volkman, founder of Trajectory Communications, said the threatening messages are actually bringing spouses closer together.

Behind the scenes, the military community "is rallying big time, so if the intent of that was to invoke fear ... it's having the opposite effect," Volkman said.

"I'm proud of that response," she added, noting that people have been writing encouraging comments such as "No Fear!"

She said she notified her husband and sent him copies of the messages. The spouse whose account was hacked contacted the local police and the FBI, Volkman said.

Those were good steps, officials say.

Jenny Shearer, an FBI spokeswoman, advises reporting such incidents to local law enforcement authorities if you are concerned about your safety. You should also call the local field office of the FBI, listed on the FBI's website. The Bureau also has field offices in a number of overseas locations.

Every situation is different, but if there is criminal activity is involved that could affect the military, officials say troops and family members should contact local military criminal investigators.

When service members' accounts are hacked, military guidance is to notify the chain of command immediately, and if possible, suspend all accounts to prevent further problems. Follow the instructions from your specific social media platform — i.e., Twitter, Facebook, Instagram — for reporting the hacking incident.

Report the incident online to the IC3 at www.ic3.gov, Shearer said. IC3 is a partnership between the FBI and the National White Collar Crime Center to receive Internet-related criminal complaints. IC3 researches, develops and refers these complaints to the appropriate federal, state, local and international law enforcement agencies.

Shearer declined to comment on whether the FBI is investigating the particular incident involving the military spouses. "We generally don't confirm or deny an investigation," she said.

Following the reports of the hacking and the malicious tweets to spouses, defense officials reposted their "Guide to Keeping Your Social Media Accounts Secure" to five online platforms geared toward military spouses, said Pentagon spokesman Navy Lt. Cmdr. Nate Christensen. That guide was produced in January.

"We encourage our service members and their family members to be careful regarding sharing their personal information," Christensen said.

Among the many protective measures to consider to reduce the risk of a malicious cyber attack:

  • Use a strong password that includes a variety of letters, numbers and special characters. Use one that is randomly generated or a random string of words. Use a unique password for each website or service. Protect your computers and mobile devices with strong passwords.
  • Don't give your user name and password to untrusted third parties, especially those promising to get you followers or make you money.
  • Use a government email address, if possible, or other private-domain account; they are generally more secure than a public service. If you use a public email provider, consider added measures such as Gmail's two-factor authentication.
  • Keep your computer and operating system up to date with the most recent patches, upgrades and anti-virus software.
  • Download applications with care. Revoke access for any third-party application that you don't recognize by visiting the "applications" tab in your account settings.
  • Keep your firewall turned on.
  • Turn off your computer. Being "always on" renders computers more susceptible to attack, the FBI says.

For more information about protecting yourself against cyber attacks, and information about reporting cyber crime, visit the FBI site.