Google Frustration

I'm completely loosing my mind with some of my teachers and students. We have had discussions over and over about Google. At my department meetings where all the district librarians get together, we have discussed various search tools students should be using. We have several online subscriptions that our district subscribes to. We have links on our school website to these and others student-friendly search tools that are good for students. When our discussion turns to Google, we have decided that this is not a search engine our elementary students should be using, maybe as a last resort, but not right away. Our main thinking for this is due to the fact that searches will bring back way too many hits and that the sites are not filtered to eliminate ones that are not appropriate for students.

Here's the story:

Students were being sent to the computer lab, unsupervised, to search for information on a particular topic.
PROBLEM -Unsupervised? WTF? This is not the model class of our school and these kids have no idea how to conduct an effective internet search.

Today, there were kids who came to the lab this morning looking for Civil War information. They said they needed pictures and information because they were studying it. The first thing they did is head straight to Google (only 128,000,000 hits show up).
PROBLEM -It's nice that the teacher gave them direction for the assignment.

I'm really frustrated for a number of reasons. The first is the fact that the kids are sent unsupervised, without my knowledge that they are even going to be in the lab. If I at least knew they were coming, I wouldn't be so pissed off about it, but I found out because I walked into the lab, which is connected to my library, with another class and found three fifth graders there. Another reason I'm frustrated is because they head straight to Google! Now, I'm not a Google-hater, it is a very good resource and I use it a ton. However, this isn't where kids should start. I'm at a point where I think I have a couple of options, but I'm not sure where to start.

Options:
1. Not allow students in the lab without a teacher. (We have this rule, but it needs to be strictly enforced.)
2. Remove kids from the computer and lab when I see them using Google.
3. Continue to pound into their heads the other resources they should be using.
4. Continue to pound into the teacher's heads #1 and #3.
5. Have the district block Google for elementary students.

I really know what the answers, but if you have any other options for me, I'd love to hear them.

On the other hand, because we know Google is a good resource, is it really that bad if they use it as their first stop on the information superhighway? Odds are, many of us head their first as well, so why shouldn't they? Should they learn the skill of evaluating good and bad links and pictures at the elementary age or is this something that should take place when they're a little older?