Here is an interesting point.
If you use your driver's license to obtain pot in CO or some other state with legalized pot, you have created a record.
If you obtain a firearm legally, when you complete the ATF form 4473 and answer question 11e "are you an unlawful user of, or addicted to, marijuana, or any depressant, stimulant, narcotic drug, or any other controlled substance" you disqualify yourself from firearm ownership.
People don't seem to understand what smoking "legal" pot does for your freedoms.