While there is an exam and better employment prospects may be had for those with a license, getting a license usually requires "acceptable, progressive, and verifiable work experience in the industry."[1] This often requires an engineering mentor to assess your work which usually happens if you work under a licensed engineer. Licensed engineers are hard to come by in many high tech and computer industries and with many companies strict rules on secrecy (i.e. NDAs) it can be difficult to get a licensed engineer in your field that is outside your company to assess your work.

I tried to see if there was an opportunity for an engineering mentor at my job (One of the big four) and I was unable to get anywhere. It seems that it is better for our job prospects to get a job at a prestigious/interesting company and gain experience there than try to go through the licensing process.

[1]:http://ncees.org/licensure/