Let me just copy and paste:
GPS Testing Times:
The Department of Defense is warning of scheduled disruptions to the Global Positioning System as part of interference testing. Mariners along the Florida coast and elsewhere are urged not to depend on GPS equipment during these testing times. The dates for scheduled testing are:

June 11 - 11 a.m.-2 p.m.
June 13 - 8 a.m.-noon
June 14 - 2 p.m.-5 p.m.
June 17 - 9 a.m.-1 p.m.
June 18 - 5 p.m.-8 p.m.
June 19 - 7 p.m.-10 p.m.
June 20 - 2 p.m.-5 p.m.

"GPS interference testing, conducted during a military exercise by the Department of Defense, will make the signal unreliable and may affect cell phone signals from about 50 to 60 miles off the coast of Cape Hatteras as well as some waters off Florida, the U.S. Coast Guard announced Thursday. Due to the disruptions, the Coast Guard is urging all boaters to be prepared for times when GPS may not work or may not be accurate."

I don't know how accurate this information is, I just thought it was interesting.

What's your source, Deadeye?

That info is from one of the groups that monitors terrorism-related websites and jihad newsgroups and such. I'm sorry I don't remember which one. They just posted it as an item of interest, not a terror-related item.
These sites have been pretty accurate in the past, they reported the Ohio shopping mall plot about 3 weeks ago. Way faster than the mainstream media.

one two sources and the GOVERNMENTAL ADVISORY on U.S. Coast Guard Navigation Center