Is any job worth sacrificing your privacy?
Many techniques are used today to try and evaluate who is a "good" employee.
Some employees are still being given the Minnesota Multiphasic Personality Inventory test. (test usually to determine mental illnesses) though it has been outlawed in some states outside of the medical environment.
In most cases, companies can`t ask you about religion, marital status and race in job interviews. Why should questions that are even more private be allowed after you are employed? Should you refuse such invasive tactics? Probably, but be ready for the consequences.