Is stalking illegal?

I realize that many of my short stories are kind of sad or depressing : (. I want to try and write a more upbeat piece.

"Is stalking really illegal?" asked Erin, as her best friend Jeff answered his phone.
"Hello to you, too. And yes, you crazy person. Stalking is illegal," Jeff answered with a sigh. "What did you do this time?"
Erin was offended. "Why do you always assume I've done something?"
"Because you are the only person I know who actually has a restraining order against them," he answered, matter of fact.
"Hey! You promised not to bring that up! You know that wasn't my fault!" She practically shrieked.
"Okay, Okay, whatever you say," he said, distracted by the TV.
"What are you watching?"
"CSI. Or at least I was trying to."
"You lie! I can hear Carson whats- his -face in the background. You're watching, 'How to Look Good Naked!'"
Jeff was annoyed. "Shut up. So what?"
"You are the only guy I know that would watch that show. You know they don't actually show you a naked girl, right?"
"Well, you are the only girl I know who is literally CRAZY!"
"Whatever," Erin said defensively.
"I don't get why the girl always acts shocked when he says they're going to do the shoot naked. I mean don't they watch the show? It's the same every time!" Jeff cried passionatly.
She sighed. "God, you're such a girl."
"At least I'm not crazy."
"According to....? Who? You're ex girlfriend? She thinks you're pretty crazy," Erin reminded him.
Jeff was silent for a minute then answered slowly, "We agreed never to talk about it again, right?"
"Okay fine, I won't say another word...if you could just go with me tonight to..."
"To what? You want me to go stalking with you don't you? What's his name this time anyway? No wait! Don't tell me. The less I know the less chance I have of being incriminated."
"God, you're dramatic! I am not doing anything wrong. I just want to go see where he lives, and maybe works," Erin said quietly.
"Fine," said Jeff, exasperated, but bored enough to go along. "But you're buying dinner."