Fish and Game Code 7149.3, written by the California Legislature and signed by the State Governor, makes it the law that a license is not needed to collect rattlesnakes:
"Notwithstanding Section 7149, a sport fishing license is not required for any resident to take any rattlesnake (genus Crotalus or Sistrurus)." (The inclusion of genus Sistrurus is not necessary since that genus is not found in California.)
The regulations regarding reptiles state that "No sportfishing license is required for the sport take of any rattlesnake, but bag and possession limits do apply."
This law regarding rattlesnakes was not written by CDFW, but the agency enforces the law and has imposed bag and possession limits on rattlesnakes Some people interpret the no-license-required regulation to mean that they can collect, kill, or possess as many rattlesnakes as they want but this is not true. For all species of rattlesnakes the CDFW regulations show a daily bag and possession limit of two.
My opinion is that this law exists to allow someone to remove or kill a rattlesnake on private property in order to protect themselves, their family, or their animals, without having to obtain a license first. Rattlesnakes play a valuable role in the ecosystem and they are greatly misunderstood, but they are dangerous and they do occasionally cause physical harm and suffering to people and pets and the treatment for rattlesnake envenomation can be very expensive, so rattlesnakes need to be treated differently from harmless snakes.
This law might seem to encourage the unnecessary killing of rattlesnakes, however most property owners are probably not aware that they would need a license to remove or kill rattlesnakes, if that was the law, since they do not need a license to kill other "pests" on their property such as gophers and rodents. And it's also an unfortunate fact that most people will remove or kill any kind of snake they find near their home without checking first to make sure it is dangerous, and regardless of whether or not they need a license.