I wonder what happens if test-engineer Bob finds out that there is a new job-opening for a test-engineer in his company, with a salary that is significantly higher than his own current salary.
I don't do the "lets re-negotiate my salary" bit, it's up to my employer to keep me at or above market rate for my skills, I shouldn't have to ask for it.
And given the fact that this market rate is not a clearly defined value (also thanks to employers' reluctance), don't you think it is necessary to at least negotiate with your current employer if you believe you're being paid below par?
That being said, if I wasn't privy to this information it wouldn't take much to find out what the other people on my team are making. I don't think I've ever worked in an environment where salaries were considered top secret information.
Compare with "What happens if engineer Bob finds out that his company has finally conceded to the current market rates, if only for new hires, but expects to continue under-paying their established employees?"
In most cases, businesses are reasonable. They aren't going to volunteer to pay you more out of the goodness of their heart, but (most) of the time it doesn't hurt to ask. Just don't go threatening to leave if they don't.
Sticking around for the original salary after renegotiating tells them either that you didn't care that much to begin with, or that you'll be taking a lot of calls and personal days in the next couple of months.
I really don't understand why companies are so nonchalant about employee retention.