While I was finishing up my tasks after picking an anchor spot and setting into it, a powerboat went and anchored about 130 yards upwind of me. Thought it was totally rediculous that they would be anchoring right in behind (20 yards) the rocks of RedFish Island but figured...oh well...wind shouldn't change until the morning. Then I thought...if they are that close to the rocks, they can't be putting much anchor out. Then I thought...well...only supposed to be 2 knots tonight. So I continue on with my chores and let them do their thing.Later on I realized sometime while I was busy, a large sailboat and another large power cruiser came and rafted up. It was already dark and they were partying and I was re-thinking my decision of not saying anything to them. I came to the conclusion that it shouldn't be a problem and I know I'm going to get shit if I warn them. It was a crowded anchorage and I had one of the best spots...if not the best spot so I didn't want to move either.A couple hours later I was trying to logon to the web but my data cable broke. Then I had the bright idea of checking the weather by my cellphone. As it turns out, all that decision did for me was cause me to lose some sleep and others as well. The new weather report had the wind changing directions overnight. I use a Danforth which we all know doesn't reset well so I decided to sleep in the cockpit with the gps anchor alarm on.About 1:30 am the wind changed directions (Anchor alarm woke me up due to the shift). At about 3 am the wind picked up to 15, gusting to 18. I was a little worried because I couldn't tell if I was still on the original anchor set or if it had already reset itself so when I herd an anchor alarm, I woke up quickly because I didn't have much room before I would be barring down on another boat. My boat still hadn't moved at all but those 3 rafted up boats were dragging at about a knot. I put my very bright spotlight on them and blew the horn. I think everybody in the whole anchorage woke up except for the drifters. I saw many boat owners checking their anchors and nerviously watching the drifters to see where they were going to go. Luckly, all downwind boats were missed. They may have hit an old oil pump pole; couldn't tell they were about a mile away, but they finally woke up and seperated and drove off one by one.I went back to sleep in the cockpit and woke up 2 hours later when the sun came up. My boat still hadn't moved but the wind was still strong. I figured if it held that long, it will hold the rest of the time so I went down below and back to sleep. Finally was able to get some good sleep thinking that if I don't hear the anchor alarm and I do drag, somebody will see it and wake me. At 10 am when I woke up, boat still didn't move from it's shift after the wind changed. I still don't know if the anchor reset or it was still holding off the original set I put in. In any case, all is well on my end but others had a bigger scare then I did; thanks to the wind shifting directions before it picked up.From now on, if I see a knucklehead, I'm going to tell them they are a knucklehead 