To Lock, or Not to Lock?

To lock, or not to lock?
Many travel advice columns advise people to lock their suitcase before checking bags in.
Unless care is taken, this act will -more often than not- get you a broken lock and a note from TSA indicating that they had to break into your bag for security reasons. Why?
The rules of travel have changed drastically since 9/11 and baggage handlers must be able to inspect any suspicious bags (locked equals suspicious, according to the TSA representative I spoke with).

So what can you do? Most airport shops and travel retailers now sell TSA sanctioned locks for your bags. These locks can only be opened by you, the bag’s owner, or with a master key in possession of official TSA agents. And no worries, the TSA Master Key is government issued and cannot be purchased over the counter by thieves.