Its an old problem, and not made any easier to deal with because the army has a top secret network (SIPRNET, that operates just like the Internet) that is available only to people in the army. Its easy for troops to be doing something on SIPRNET, then switch to the Internet, and forget that hes now on an unsecure network. The warnings from the general will not cure the problem. The Internet is too useful for the troops, especially for discussing technical and tactical matters with other soldiers. The army has tried to control the problem by monitoring military accounts (those ending in .mil), but the troops quickly got hip to that, and opened another account from Yahoo or Google, for their more casual web surfing, and for discussions with other troops. The Internet has been a major benefit for combat soldiers, enabling them to share first hand information quickly, and accurately. Thats why the troops were warned that the enemy is actively searching for anything G.I.s post, and this stuff has been found at terrorist web sites, and on captured enemy laptops. In reality, information spreads among terrorists much more slowly than among American troops. But if soldiers discuss tactics and techniques in an open venue, including posting pictures and videos, the enemy will eventually find and download it.
The Chief of Staff of the U.S. Army recently sent out a reminder to all the troops, to be careful what they said, or posted, online. Many soldiers have been found discussing details of how they operate, including technical details that are considered Top Secret. No one has been court martialled, but the number of cases has been alarming.