In the last few weeks, Christina DesMarais has lived in a state of fear.

The writer, triathlon runner and mother of four started a nutrition and fitness blog a few weeks ago and noticed someone kept posting nasty comments. Eventually, she started receiving hurtful e-mails as well. Last week, a letter came in the mail.

"I'm the middle-aged man in the turquoise junker or the teen in the silver Camero (sic) or maybe even the woman in the Suburban -- I wouldn't be caught running down my road again if I were you," the anonymous letter said.

Read the full letter

"The last letter was a rant about us being white trash who use the system, while hardworking taxpayers foot the bill for our lavish lifestyle," said DesMarais, who originally posted public comments about the harassment but has since removed those posts and contacted local authorities.

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It turns out that cyberstalking laws do help protect victims traumatized by repeated communications on blogs, social networks, and abusive e-mails, although the exact laws vary from state-to-state, said Parry Aftab, an Internet privacy and security lawyer, book author, and executive director of WiredSafety.org. Aftab also advises Facebook on cyberharassment policies.

"Digital harassment violates a federal statute, which says anonymous communication with intent to annoy is now a federal crime that carries a two-years prison term and pretty serious fines," she said.

However, Aftab said no one has been prosecuted under that law, which was enacted in early 2006. In many cases, local authorities are ill-equipped and reluctant to deal with cyber-investigative techniques, and "in a lot of cases results in nothing more than an expensive speeding ticket" she said.

Is Cyberstalking a Serious Cause for Concern?

For those who spend hours on the Internet, it's hard to know when anonymous posters are just poking fun or making negative comments and when you are actually being stalked.

"Cyberstalking usually involves a course of conduct, more than one instance, that would cause a reasonable person fear," said Michael Kaiser, the Executive Director of the National Cyber Security Alliance. "E-mail, text messages, and harassing on websites are considered stalking in a lot of instances and a sign that things are turning." 

Kathleen Baty, the CEO of Safety Chick Enterprises, was stalked from 1982 to 1990. She was kidnapped and held at gunpoint in an 11-hour standoff with police until she was finally let go. She now advises ESPN anchors and celebrities on how to deal with cyberstalking.

"Stalking can take all forms," said Baty. "If someone is following you or fixating upon you, sending you e-mails, waiting to show up at your door, it falls under the same umbrella of stalking."

Baty said there is a gray area to cyberstalking. This form of harassment could be a random hacker messing around on the Internet, or it could be someone watching you and wishing you harm. However, whether it's on the Internet or in person, the stress and turmoil is just as real.

"This is stalking, it's just that the means of getting to you is through the Internet," she said.

Jeff Lanza was an FBI special agent for 20 years and now works as a security specialist. He said the difference between a harmless Internet nastygram (which seems all too common these days) and real cyberstalking is the intent to do physical harm.

Interestingly, the concept of "trolls" who just annoy for pleasure have been around for decades. But new social networks such as Facebook are designed for more intimate connections.

Krystal Jones, a marketing professional from Columbus, Ohio, said Facebook cyberstalking became "a horror story" but was resolved quickly. She had connected with a former friend on Facebook, but then started receiving e-mails and wall postings from his spouse, laced with foul language.

She was accused of having less than noble intentions in connecting with the former friend. Jones dealt with the issue by using use the friend-blocking features on Facebook.

"Facebook  allows people to control how their information is shared and who's able to contact them," said Simon Axten, a Facebook spokesperson. "We have automated systems to detect and block suspicious or potentially dangerous behavior, such as sending many messages to non-friends in a short period of time or friend requests that are ignored at an unusually high rate."

How to Deal With a Cyberstalker

Baty advises to take note when online communication seems to be taking the form of repeated abuse.

She said it's important to keep a file of all communications on blogs, social networks, e-mail and through the post office. And retain the actual digital copy, which may contain an IP address. She advises to examine your "security perimeter" and determine whether you feel safe online or if you have revealed too much information about your personal life.

Aftab has coined the term "good digital hygiene" for a way to live securely on the Web. She said not to use obvious passwords or reveal personal information, and to make use of the privacy settings on Facebook, Twitter.com, and other accounts that can hide your exact birthdate and address.

Lanza said it's true we live in a digital age where people will sometimes vent online and flame each other, and Aftab agreed that we need to develop thick skin to the occasional cyberjab.

However, criminals do use social engineering tactics to harass their victims. Aftab said a hacker might try to break into your Facebook account and post pictures or messages that get you kicked off the site. The goal is sometimes to annoy you, but some initial contacts can lead to more nefarious activity. She advises never to engage a cyberstalker in more communication, since that is often the goal.

Lanza said our identities are wide open on the Internet. Hackers can use a reverse e-mail search to find your personal information, such as your spouse's name, using a site such as Zabasearch.com. Once a criminal has your physical address and birthdate, they can often steal your online identity.

For DesMarais, it's not important how the cyberstalking started or how it's defined -- the goal now is to make it stop before it escalates further. It has started causing real emotional pain.

"I worry all the time if this person is going to hurt me, or do something to my family in order to hurt me," she said. "We have had to invest in a security system, which is costly. I have had to alter where I run, avoiding places that are remote. I worry that the stalker will get into our house when we sleep. The many ways someone could hurt us is endless and I think about those possibilities every day."