I know that currently in the states they are looking to vote on the legalising of marijuana in various states (it's already legal in a few), this got me thinking that lets say a law was passed (both local and federal) which made pot legal would this mean that all people who are currently serving time in prison for say growing or distributing/or if they have a record for being caught with it (basically any crime based on using/selling/growing/having marijuana)...would these sentences/convictions be overturned and persons released?

http://www.washingtonpost.com/blogs/govbeat/wp/2014/10/13/where-marijuana-is-legalized-decriminalized-or-on-the-november-ballot/

Same thing with any other illegal action being made legal - like prostitition.

Thoughts?