There's different levels of "replicas" - replicas are just items that are manufactured without the proper licensing. Importing fake 100 DVD's is very different than importing 100 unlicensed spongebob stuffed animals (likely to be given as prizes at Carnivals and Fairs across the U.S.). This is because there are previously existing issues where motion picture companies have informed Customs of the rules and what to look for.
Do people go to jail for importing bootleg crap? Yes, all of the time. A guy I knew from another online forum boasted about finding this uber secret source of iPads. He bought 200 of them and sold them. He imported another 200. Got a notice they were confiscated by customs. Decided he was smart by ordering another 200 and having them delivered to his parents house. He was raided, his parents house was raided, he was arrested, thrown in jail (awaiting trial), his house is likely to be confiscated and sold to pay for his judgement, his wife couldn't access money in his bank account they they legally earned, etc.
I'm not saying don't import replicas, just don't import stuff like Apple products and Nike and the stuff where a billion dollar company has to fend off bootleggers.
