It might be a combination. It seems the police are taking a greater interest. The bicyclist stabbing and the fataility hit-and-run suspects were all arrested.
However, it may also be an increase in cyclists with less respect for motorists too. A friend of mine told me he joined one of the weekday training rides and was appalled at how a group of 20-30 cyclists heeded no red lights, swerved in and out of stopped traffic (waiting on red or stop sign they were going to blow), yelled at motorists, consumed the whole lane, and stopped to talk without getting out of the road.
IMO, the lack of cycling education, either through classes or "group ride nazi" is compounding cyclist behavior since they were wronged doing what they originally thought was best (primarily hugging the right side), and then adjusted to an offensive-defense behavior when being "out of the way" didn't work.