The sign does give you the option to either move over OR slow down.
But my question is...
Is it really an “emergency” to give some poor slob a speeding ticket?
If it’s a true emergency, then fine. Otherwise the 90 percent of the time cops are on the side of the road for such emergencies, then I wonder why they just don’t tell that speeder to head for the nearest exit so they can continue their revenue collection process?
Which is the case in most states. The bogus part of many of these chain emails is the speed at which you may pass the emergency vehicle while staying in the right lane. Most laws say "safe and prudent", or something to that effect.
However, I've seen some emails saying that you need to slow to 30 mph. That's BS and it will cause an accident.