+1 for speed limit data in Waze.
I see many different (and strange) arguments against it in this thread.
If you don't want your Waze to tell you the speed limit, or whether you are speeding or not, then of course it must be possible to turn it off.
To describe how Waze somehow could get sued for this - well, as another poster said: if Garmin, and Sygic, and TomTom, and probably many more, can provide this info without the risk of being sued, then why can't Waze?
Except for when you're in a tunnel, Waze will probably give you a much more correct speed than your speedometer which has been "factory set" with a fault margin to allow different wheel sizes etc. Typically a car's speedometer has a fault tolerance within 10%, but always so that it tells you a slightly higher speed than what is the actual speed of the car (so you shouldn't be accused of speeding based on what the speedometer tells you) - good for you, bad for the ones behind you with GPS showing them that you are constantly driving below speed limit
How to get the speed limit data?
Well, I would guess that on roads frequently travelled by Wazers, Waze could 'guess' the speed data based on historical data.
Local Wazers could probably help by entering speed limits in the Waze map editor.
But one other solution, that I would guess could work and would give 100% correct data, would be for Waze, or Google, or Waze reps in the respective countries, to ask the "department for traffic" for the national speed limit data.
This might seem impossible, but it's not.
Why should the government "hide" this? Their interest should be to share these data with as many (drivers) as possible - remember that the speed limits are not there in order to collect fines, it's there for safety reasons.
In Norway, data like this has been, and are still being, released in open formats (think 'set the data free') *, so I would assume/hope that Waze (and other driving apps/units) could use data received directly from 'the source' (but of course still with disclaimers that the Driver is solely responsible bla, bla, bla).
*: http://www.vegvesen.no/Fag/Teknologi/Na ... In+English