Thursday was April 20th, or 4/20, a day that is celebrated by many marijuana lovers.

To commemorate the occasion, advocates for legalized pot handed out free joints to congressional staffers and reporters on Capitol Hill.

The giveaway happened on a city street next to the U.S. capitol. Activists say they were within their rights, but Capitol Police didn't see it that way.

RELATED: 7 arrested for possession of marijuana on Capitol Grounds 

Seven people were arrested on possession charges and led away. D.C.’s marijuana law has been in effect for two years. Still, not everyone understands what's legal, and what's not.

It is legal for a person who is at least 21 years old to have no more than two ounces of marijuana to smoke on private property.

A person can give another person no more than one ounce of marijuana as long as there is no payment made or any other type of exchange of goods or services are exchanged.

In addition, up to six marijuana plants can be grown inside a home. A person can possess marijuana-related drug paraphernalia that is associated with no more than one ounce of marijuana.

It is illegal to possess more than two ounces of marijuana, smoke it in a public place (like a car or any street) and sell any amount of marijuana to another person. Marijuana possession by persons under 21 years of age is not allowed.