What activities take place in the warning areas offshore of Washington, D.C.? Looking at the Washington sectional, several areas offshore are designated "Warning" areas: W-386, W-107, W-105 etc. The only notes given are "National Defense Operating Areas. Operations hazardous to the flight of aircraft conducted within these areas". 

That would be enough to keep me well ashore, but out of morbid curiosity, what kind of activities are we talking about? Are these areas designated for naval gunnery/missile ranges?
Answering my own question, these areas are designated for a variety of naval training and testing exercises including missile launches and heavy guns firing, which is the primary reason it's hazardous. The airspace can be traversed under guidance from either Washington Center or FACSFAC VACAPES, but entry by VFR aircraft without established comms is not recommended.