All of the members whose accounts were hacked said they had recently logged onto their Facebook pages using the free and open WiFi service the Legislature provides, the St. Louis Post-Dispatch reported Monday.
"If the reports are true, this is a spike in what we've experienced in the past," said Adam Crumbliss, the House clerk. "We're hearing more about it than we ever have."
A free, downloadable program called Firesheep targets WiFi users' private account information, the newspaper said.
Freshman Missouri Rep. Donna Lichtenegger, R-Jackson, was one of the lawmakers whose account was hacked.
"I love lobbyist! (sic) All the free food and stuff you get. This job is awesome!" the post on her Facebook page read.
She said the day her account was compromised she had used the Legislature's open WiFi service to log onto her Facebook page. Just a few hours later, her account was hacked.
Cybersecurity expert James Lewis said grabbing personal information via Firesheep is a fairly simple procedure, but he stopped short of saying that's how the accounts were hacked.
"It's worth trying to figure out if this was a wireless problem or a password problem," Lewis said. "That would give you an idea of what defense you need."
The Facebook page of Rep. Dave Schatz, R-Sullivan, also was hacked. The Internet intruder posted information similar to that posted on Lichtenegger's Facebook page.
"I didn't know where this was coming from, so I didn't say anything about it," Schatz said.