All are impressive pieces of technology, but also tools too frequently misused by the modern stalker.
At a Department of Justice event marking January both as National Stalking Awareness Month and the 15th anniversary of the Violence Against Women Act, Associate Attorney General Perrelli said the use of technology by stalkers has become "a common practice."
"We must recognize the changing nature of these crimes and develop new strategies for addressing them," he said. "We in law enforcement, and our partners in the judiciary, need to adapt in order to stop those who stalk and provide help to victims of stalking."
As smaller and cheaper technology and social networking sites proliferate, victims' advocates say it is becoming easier for stalkers to monitor and terrorize their victims.
But though the technology presents new and formidable challenges, experts say law enforcement and stalking victims are learning to beat offenders at their own game.
One-Quarter of Stalking Victims Report Cyber-Stalking
A Department of Justice report from January 2009 said that about one-quarter of the 3.4 million stalking victims in the United States reported cyber-stalking, such as e-mail or instant messaging. GPS technology and other forms of electronic monitoring were used to track one in 13 victims.
Though the behavior isn't new, experts say new tactics and technology sometimes stump law enforcement, which is often understaffed, under-resourced and under-trained.
"Technology has not created a whole new breed of stalkers but it makes it easier to engage in [that] behavior," said Michelle Garcia, director of the National Center for Victims of Crime's Stalking Resource Center. And, she added, the technology sometimes overwhelms law officers.
"In many instances, they don't understand the technology or they're not familiar with it," she said, adding that sometimes "they don't even know technology can do what some of the victims are reporting."
Law Enforcement: Privacy Laws Sometimes Help Stalkers Stay Ahead
But some officers around the country are learning to use technology against the highest-tech offenders.
Deirdri Fishel, a police detective in State College, Pa., said that in many cases, privacy laws help stalkers to stay one step ahead.
If an offender uses anonymous e-mail sites to harass victims or anonymously creates a Web site publicizing personal information about a victim, investigators often lose valuable time filing court orders or asking Internet companies for records, she said.
Though she understands why the laws are important, she said they can still be challenging when police are trying to crack a case.
But in some cases, she said technology can help law enforcement get past those obstacles.
"We're using the technology to catch the stalkers in the same way they use technology to perpetuate stalking," she said.
Digital Stalking Leaves Behind Digital Trail
For example, though stalkers may use the Internet and disposable phone cards to monitor and torment victims, they also resort to lower-tech tactics too. Fishel said they'll often follow victims or drive by their homes or damage their property.
To catch the stalkers in the act, she said she and her partner will install surveillance equipment at victims' homes.
Though they can't always monitor the video in real-time, the video cameras give victims peace of mind and the footage serves as valuable evidence that can be used in court.
She also said that digital stalking leaves behind a digital trail that can help build a case against a stalker.
Though a victim's first instinct might be to delete a threatening text or e-mail message, Fishel urges victims to save everything.
If you delete e-mails, she said, "You lose the trail to be able to go back and be able to trace it to the original source."
She also said that since much of the data stored by Internet companies like Yahoo, Hotmail and Facebook is purged after a certain amount of time, people who think they are being stalked should get in touch with law enforcement sooner rather than later.
Once law enforcement has been notified, officers can initiate a process requesting that tech companies save potentially incriminating email messages and other data.
Victims' Advocates: Trust Your Instincts
Experts say that if you think you're being stalked, you should trust your instincts.
"If you think someone knows too much about your activities, it's entirely possible and likely that the stalker is misusing technological tools to surveil and terrorize," said Cindy Southworth, director of technology for the National Network to End Domestic Violence.
A trip to the computer store with your home computer or laptop can help determine if someone is monitoring your online activities with spyware. But, if you're suspicious, Southworth cautioned against searching for "spyware" or other related terms on your home computer.
If someone is indeed watching you electronically, those key words could tip him off and potentially escalate the harassment, she said, adding that a safe alternative could be a computer at the local library.
Safety experts also encourage victims to change their passwords and even e-mail accounts, as stalkers are often former intimate partners who might know that a password contains birthdays or pets' names.
Southworth said that though technology can be intimidating, it can also become one of a victim's strongest allies.
"In the past, a lot of pressure was put on the victim as the only witness to stalking," she said. "Now if you have e-mail, text messages, camera footage, you have incredibly powerful evidence."