Motorcycles

I hate motorcycles on the highway. Here in LA, it is legal for them to drive between lanes on the dotted line and weave between traffic. They sneak up on you and come so very close to your car. It is scary. Cars are always switching lanes so quickly and bikes get right in your blindspot. Why would this be legal? I can understand them going between lanes when the traffic is really slow or stopped...then it makes more sense and is not as dangerous. My problem is when they do this when traffic is going at full pace. Just because they are a motorcycle, they think they can go 10 miles over the speed limit (and often more than that) and still whip between lanes. Couldn't they revamp the law to only allowing them to go between cars if the flow of traffic is under a certain speed limit?