Los Angeles County sheriff's officials today cautioned parents to be vigilant about their children's online experiences with social networking sites, the number of which is growing.

Parents should explain to their children what sort of information should be kept private, such as their full names, addresses, social security numbers, phone numbers and family financial information.

Officials also suggest that children use screen names that do not reveal too much about themselves.

Parents should also use privacy settings to restrict who can access and post on their children's websites.

"Some social networking sites have strong privacy settings.

"Show your child how to use these settings to limit who can view their online profile, and explain to them why this is important," reads an advisory issued by LASD.

Children should also be told to publish only information that they are comfortable with others seeing, the advisory states.

"Even if privacy settings are turned on, some -- or even all -- of your child’s profile may be seen by a broader audience than you’re comfortable with," reads the advisory.

"Encourage your child to think about the language used in a blog, and to think before posting pictures and videos. Employers, college admissions officers, team coaches, and teachers may view your child’s postings."

Screen names could even make a difference, giving bad or good impressions.

"Remind your kids that once they post information online, they can’t take it back. Even if they delete the information from a site, older versions may exist on other people’s computers and be circulated online," according to the advisory.

According to officials, kids are more often accessing the Internet through their cell phones and parents should determine how they can use parental controls on the phones, officials said.

"Some cellular companies have plans that limit downloads, Internet access, and texting; other plans allow kids to use those features only at certain times of day," the advisory states.

Officials also warn parents to be aware of online bullying and to ensure their children are neither victims, nor victimizers.

"Tell your kids that the words they type and the images they post can have real-world consequences.

"They can make the target of the bullying feel bad, make the sender look bad -- and, sometimes, can bring on punishment from the authorities."

Online sex talk is also a possibility so parents should be vigilant, lest their children connect with a predator.

"If you’re concerned that your child is engaging in risky online behavior, you can search the blog sites they visit to see what information they’re posting.

"Try searching by their name, nickname, school, hobbies, grade, or area where you live."

Parents should encourage their children to come to them if they feel threatened or uncomfortable by something they see online and, if there is reason for concern, report it to police and the site's webmasters.

"Spend some time with a site’s privacy policy, FAQs, and parent sections to understand its features and privacy controls," the advisory reads.

The site should spell out your rights as a parent to review and delete your child’s profile if your child is younger than 13."