When a person is convicted on federal felony charges there are a variety of legal consequences, some of which aren't limited to prison time. For example, people convicted of a felony aren't allowed to own a firearm. Simply owning a gun under these circumstances can result in serious criminal charges.
Rapper Gucci Mane, who is legally named Radric Davis, was recently struck with two counts of federal charges for possessing a firearm as a convicted felon. In total, Mane could spend 20 years in prison if he's convicted and handed the maximum sentence.