I have to disagree with the idea of letting them take stuff. That just serves to encourage and embolden the vermin. I have the right to remain unmolested on my property. Sure, the stuff out there, for the most part isn't worth killing for. But, I worked hard for all I have, and I'll be a monkey's uncle if some jerk is gonna get an early christmas in my backyard while I watch. It's the principle of the thing, not the property value.
First, I call the cops and report the problem. I my neck of the woods, response time is about 2 minutes, and the cops tend to side with homeowners, especially when they're a block captain for the neighborhood watch. 2nd, I'll tell them from the back door to get lost. 3rd, I release 260+ lbs of dog. If that doesn't work, I'll probably go over and start busting up my shed with a shovel. That oughta freak 'em out. I'd rather destroy my own property than let some meth freak have it.
On the topic of avoidance being best, sure. In public, I'll back down and walk away to avoid a shooting. But I won't be run off my land. That just isn't me. I mean, where does it stop? Today, it's my shed stuff. Tommorrow, my TV. Next week, they'll just slap me around, but hey, they said they wouldn't kill me, so it's ok? Just lie there, honey, they'll be done soon, and we don't want to face charges. It's a slippery slope(gods, I hate that cliche!), and a bad one to start down.
How about this. What if they are stealing your friendly dog? Just property, right? I don't know about you, but they're family, almost like children. Sure, I'll send them out to fight, that's what they're for. But should we let someone take them?
That is a fundamental error legally and tactically to approach and attempt to hold them. You are putting yourself in harm's way unnecessarily. Can you really say you are in fear for your life in this situation? On top of that, how many of us here have the legal authority to hold someone against their will? I personally am not a sworn officer of any kind and have no legal authority to stop these guys.
Many states have a concept of citizen's or private person's arrest. If you witness a crime in progress, in most cases you can detain legally using whatever force is neccessary. Also, it may be a legal error to approach, but it's the right thing to do. If we allow the barbarians in, they will tear down society. Look where compromise got us until we started fighting back on gun rights. Sorry, no compromise, and no quarter to the bad guys.
My family hardly ever did "the right thing", that's why it's important to me that I do. I may go to jail for it someday, but at least I'll have that cold comfort while I sit in my cell.
Rant over. 
On that note, read FortyFive's sig line, just above my post. Says it all.
