Janet Killen spent $5,500 and four years of effort earning what she thought was a master's degree from Canyon College, an online school originally based in Idaho.

But when she presented her nursing degree in 2007 to Lane Community College in Eugene, Ore., where she teaches nursing, she was devastated to learn it had no value. Furthermore, she was told, she could face civil and criminal charges for passing the degree off as legitimate. "I felt really violated," Killen said. "I worked very hard for this degree." Killen isn't alone. According to the state of Oregon's Office of Degree Authorization, some 4,000 other students have been cyber-scammed by Canyon College alone, and thousands more have been victimized by other schools.

The problem: The organizations these online schools say have accredited them are often bogus themselves. "Proper state registration and academic accreditation are the two most critical issues for any potential student to be aware of. These accrediting agencies can be found on the U.S. Department of Education's Web site."

Top 10 List of Accredited Online Colleges and Universities

1. DeVry University Online, Naperville, IL

2. University of Phoenix, Phoenix, AZ

3. American InterContinental University Online, Hoffman Estates, IL

4. Kaplan University, Fort Lauderdale, FL

5. Capella University, Minneapolis, MN

6. Westwood College Online, Denver, CO

7. Walden University, Minneapolis, MN
8. Strayer University, Newington, VA

9. Jones International University, Centennial, CO

10. Grand Canyon University, Phoenix, AZ