You can't find Derek Kennedy, an emergency-room physician intern in Detroit, on Facebook.
Nor will you find Mariah Prussia, a professional fighter and fitness center owner in North Dakota.
At least not under their own real names.
Last summer, their Facebook accounts were hijacked and the passwords were changed, locking them out.
Both could only watch as someone else posted videos and text on web pages they created and whose web addresses carried their names for months.
"I exhausted all the avenues," Kennedy, 30, told CNBC in a phone interview. "I want answers and I want my account back."
Says Prussia, "Individuals should understand Facebook does not have a support number or very good follow-through when it comes to hacking."
CNBC shared the web address of Kennedy's account with Eric Feinberg of the Global Intellectual Property Enforcement Center, which tracks and analyzes terrorism, hate speech and other illegal activity on social media worldwide.
Feinberg says he's not surprised by the hacks and pointed CNBC to YouTube videos with step-by-step instructions, in both English and Arabic, on how to hack into Facebook accounts.
"This is a cottage industry in the Middle East," Feinberg says. As for the hackers' motives, "It's possible they (the hackers) can't have their own accounts under authoritarian regimes," he speculates.
A YouTube spokesperson said any videos that include such content would violate their terms of service, yet a search for them on Thursday turned up thousands of results.