The Sudden Urgency of Terrorism

When the original assault weapons ban was signed by President Clinton, you heard nary a word from anyone about how these weapons could be used for 'terrorist' purposes. Now that terrorism is portrayed as the shadow behind every decision (better textbooks for our kids, or they'll become terrorists!) we are suddenly concerned with what they might do with a semi-automatic weapon that they had theoretically purchased within legal limits. My question is this: what are the odds that a terrorist is going to walk into Bob's Guns'n'Beer and pick up an AK-47 after filling out the paperwork first? And why bother when there are so many illegal guns on the market?