SEATTLE -- Do your kids use Twitter? Then listen up.

The messages your kids get could include content you don't want them to see.

Twitter messages - or Tweets -can include both pictures and links . And some of these links are clearly inappropriate for kids because they lead to pornography and other adult material.

Khon Lu owns a coffee shop, and uses Twitter as a business tool. But while tweeting for customers, Lu is dealing with an unexpected Twitter issue -- links to pornography.

"I was surprised," he said. "Caught me off guard."

The Twitter site lets users do more than just send messages. It lets them give access to followers who will read those postings. Typically it's the unknown followers who are sending the inappropriate links.

"The sex thing -- I really find disturbing," Lu said.

Twitter users can make their accounts private. If they don't, they open the door to anyone who chooses to send an inappropriate link. That's something parents may not know, but definitely should.

"It has this look to it that says, 'I am nice, I am friendly.' The word Twitter itself is very friendly. 'Twitter, twitter.' It is something birds do. How can birds be bad? Well, bird flu," said technology expert Jay Lee.

Lee says click one of these links and you could wind up on a site that will download spy ware on your machine. This malicious software can snag your private information and send it to the cyber-thieves.

"It may clearly state come look at pornography or something more innocuous like how to make money, but you do not know what is on the other side of that link," he said.

Your computer will not be infected unless you click on a link but if you do, you could compromise your account numbers and passwords.

Twitter has a way to report spam, but making your account private seems to help block most of the problems. So parents find out if your kids accounts are private and explain to them that your computer may be damaged if they follow a link to an unknown Web site.