Oct. 12, 2009  -- It's the digital equivalent of waving at someone from across a crowded room.

And yet a Tennessee woman was arrested last month for "poking" another user on Facebook.

According to an affidavit filed with the Sumner County General Sessions Court on Sept. 25, Shannon D. Jackson of Hendersonville, Tenn., allegedly violated a legal order of protection that had been previously filed against her when she sent a virtual "poke" to another woman on Facebook.

The Facebook poke feature can be used to convey a variety of meanings, including simply saying "hi" to friends, according to Facebook. When you poke someone, an alert pops up in the corner of that person's Facebook page notifying them of your poke.

Although Jackson declined to comment, her lawyer, Lawren Lassiter, told ABCNews.com that his client was "extremely shocked" when the police arrested her.

"The only evidence that I'm aware of is a printout of a screen," said Lassiter, adding that the printed screen grab of the victim's Facebook page is what led police to determine that the protective order had been breached. "I'm trying to get my hands on some Facebook documentation so we can better assess the situation."

Information from Facebook could help verify whether the poke came from Jackson's account or an imposter's, he said. It could also help determine whether or not the poke was made from Jackson's computer or if someone broke into her account.

Lassiter declined to comment on the events that led to the protective order against his client, but he said that violating an order of protection is a Class A misdemeanor that can be punished with up to 11 months, 29 days in jail. Jackson is scheduled to appear in court later this month.

The protective order against Jackson, filed on June 10, prohibited her from "telephoning, contacting or otherwise communicating with the petitioner, directly or indirectly," the affidavit said. The victim named in the affidavit, Dana M. Hannah, did not respond to requests for comment from ABCNews.com.

Facebook Poke a 'Deliberate Action'

Although "poking" is a somewhat passive and new form of technology-enabled correspondence, Ryan Calo, a residential fellow at Stanford Law School's Center for Internet & Society, said it is still a form of communication restricted by a protective order.

"A poke is a very deliberate action," he said. "You have to select the person and say, 'this is what I want to do.'"

Advances in technology have expanded the spectrum of communication, from low-engagement to high-engagement ways of interacting with others, Calo said.

This case involving Facebook "poking" is an example of how the law must recognize new and different forms of communication, he said. The digital environment can create new pitfalls and new threats, he added.

"Protective orders are not always about physical danger, they're often about getting this person out of your attention and getting away from them," he said.

In recent months, Calo said, there have been similar instances in which a person's virtual actions on social media sites have had legal ramifications.

In July, a Chicago woman was hit with a $50,000 lawsuit from a local management company after posting a comment on Twitter about her "moldy apartment."