As american citizens, we usually would "opt-in" to vote. Meaning I have to fill out and mail in my voter registration to become an eligible voter. The burdern is on us--the voters. Canada has a different law, which is the same as the new one in California.
The law signed October 2015 in California (took effect on 1/2/2015)says, as an american citizen, you are automatically registered as a voter when you go obtain your drivers license at DMV. You can of course opt out.
Non citizens, including illegal immigrants, even if they are able to get driver's licenses, they should not be registerd as voters (not opt in).
