You can't pass a car that is taking a left turn.

You can't pass 4 cars in a row like that.

These two statements are wrong in most states. Please review your state laws or the various states' laws before declaring opinion as fact.

When a vehicle is making a left turn on a two-lane highway, you are legally allowed to pass them on the right in most states if it can be done safely. Most state laws mention two conditions where you can pass other vehicles on the right – when there is another lane in that direction OR when a vehicle is making a left turn. When it comes to passing on the right, I usually end up doing it on a daily basis to someone. Several locations have since set up turn lanes for the drivers to stop blocking traffic. If you notice a place where people overtake others on the right, bring this up to your local sheriff/police department and suggest adding in a lane.

You can also overtake numerous cars as long as you are doing it safely for yourself and others. If there is three miles of empty road on the oncoming direction, seven cars going 10 MPH under, and you have the cognitive ability to get around them in a safe manner, there is nothing preventing you from doing so in most circumstances. Obviously doing something like that in the city is more restrictive, but on county roads and highways, you should be good to do so.