It depends on who you work for and what type of access you have, or, how far you are into security based electronic engineering
You can be located, attacked and destroyed in a matter of minutes depending on who wants you
That was hollywood back in the 60's,70,s and the 80's. Today its a different story
Remember the poster wants to find the user of a wireless router using software only. Sure you can electronically find the router and you'll know the user is somewhere within a couple hundred feet of it, but how do you pinpoint the actual transmission from the user to the router using only software. The router only knows signal strength, it can't know direction. If you have two or three routers (calibrated with known sensitivities) you can find a user (or one of two potential sites a user could be) but with only one router you'll never be able to do it.
You can find the general location of any user on the internet with the right software and access. But you can't find the precise position of a user of a wireless router without some SERIOUS hardware in close proximity to that user.