Craigslist.org is a useful Web site for many people, whether they’re looking to trade their old computer for a new guitar, rent out a spare room or find work. Unfortunately, barterers and job seekers aren’t the only people using it.

Scam artists have swarmed Craigslist with employment scams and get-rich-quick schemes.

According to its frequently asked questions page, Craigslist is the seventh most visited Web site in the English language – beating out Amazon and Disney – despite only having 23 employees and no subsidiary sites. It gets more than
20 billion page views a month.

This means millions of users are exposed to scams that are hard to distinguish from legitimate job offers. In addition, those who browse the social categories may encounter prostitution rings and alleged Craigslist killers who respond to personal ads.

For college students and graduates scanning for jobs and internships, the most serious issue is the employment scams, most commonly seen in companies looking for survey takers.

Recently, Craigslist started to combat this problem by warning people about the risks before they enter a job category. After making a selection, users are intercepted by a screen titled “scam alert.”

It describes “affiliate scammers,” listings that lure job seekers with non-existent compensation and has them complete several tasks or redirects them to sites that often ask for money or personal information.

The page warns against job offers that redirect people to background check, credit check and survey Web sites.

When clicking a listing, an additional warning at the top of the page recommends that users avoid anything with wire transfer or coordination through Western Union by browsing local posts only.

But these warnings are all Craigslist can do for users, aside from deleting posts that have been reported as dangerous or fake. By proceeding to the job section, Craigslist’s visitors become responsible for their protection and safety, and need to remain cautious.

Any suspicious activity should be immediately reported to the Web site administrators.

There are ways to recognize a Craigslist employment scam. Many Web sites and blogs identify and track scams, as well as warn potential targets. Popular self-help sites like ehow.com have also written about how to avoid being scammed.

Clscambuster.blogspot.com is one blog that posts a running list of Craigslist scams. The blogger relies mostly on tips from others who have been scammed or discovered them, but also posts occasional tips on how to avoid becoming a victim. The most recent scam posted is a job offer from a man named “John Bill” looking for someone to help him with his “chores.”

There are some basic precautions Craigslist users can take to avoid being scammed.

If the job listing is from a company, a quick Internet search can show the company’s start date and employees’ names. Companies with sites that don’t have their own domain or that haven’t been updated recently are suspicious.

Be wary of work-at-home jobs or offers to pay survey takers, as well as jobs with unbelievable compensation.

A recent popular scam, called the Craigslist Tutor Scam, offered around $50 for a tutor. There were different versions of the scam, but all had a foreign parent seeking a tutor for their son in different subjects – usually a language.

Craigslist claims that by dealing locally and avoiding long distance jobs like the tutor scam, users will bypass 99 percent of scams.

Jobs at local companies that actually exist and are willing to meet in person for an interview are less risky than those that hire via e-mail.

Waiting a few days to respond to an ad also has its benefits. It gives enough time to see if anyone had negative experiences with the company. Often, users post a listing after being scammed to point out which job was a fraud.

While these tips relate to employment, no section is safe from fraud. Visitors should take precaution when dealing with not only Craigslist, but also all sales and job search Web sites.

Most importantly, visitors shouldn’t underestimate the power of instinct. If a job offer seems weird, unsafe or too good to be true, it probably is.