When Star-Lord, Rocket, and Gamora were sent to jail in the first Guardians of the Galaxy, fans didn't exactly question why they were wanted by the Nova Corps. Star-Lord steals an Infinity Stone in the first act, Gamora is seen with Thanos later on, and Rocket and Groot were literally looking for people to steal from. However, a Reddit group deciphered that the stripes on the leg part of their prison uniforms represented a crime they did and director James Gunn confirmed this.
On Facebook, Gunn detailed the crimes of these characters, after correcting one of the things the group got wrong, which was Rocket participating in "indecent exposure." Gunn states that the crime lines were the idea of costume designer Alexandra Byrne, so he wrote down a list of the character's crimes.
Here are the crimes of each member, according to Gunn:
Rocket's are mercenary activity, grievous bodily harm, arson (he blows up a lot of stuff), escape from prison, and, I believe, public drunkenness.
Quill's crimes are penny-ante robbery, grift, criminal conspiracy (from his gang involvement with the Ravagers), and having sex with members of a royal family (consensual but on some planets considered an outrageous crime for someone from his caste).
Gamora keeps things simple with her long list of murders and assassinations, all at the behest of Thanos.
And Drax's crimes are grievous bodily harm, murder, and every variety of destroying stuff you can imagine.
All these details show that Gunn really thinks hard about these characters and their past. It shows how passionate he is about this franchise since these are never fully detailed in any of the movies. He showed this same attention to detail in Guardians of the Galaxy Vol. 2 and will likely show the same enthusiasm for Guardians of the Galaxy Vol. 3.
We will see the Guardians in action again on Avengers: Infinity War, which shows on May 4, 2018. They will also be in Avengers 4 on May 3, 2019.