Here's an excerpt from the US Customs and Border Protection website at
http://www.cbp.gov/xp/cgov/travel/va...ightedArticles
"Articles bearing marks that are counterfeit or inappropriately using a federally registered trademark are subject to seizure and forfeiture. The importation of articles intended for sale or public distribution bearing counterfeit marks may subject an individual to a civil fine if the registered trademark has also been recorded with CBP. Articles bearing marks that are confusingly similar to a CBP recorded registered trademark , and restricted gray market articles (goods bearing genuine marks not intended for U.S. importation for which CBP granted gray market protection) are subject to detention and seizure.
However, travelers arriving in the United States may be permitted an exemption and allowed to import one article of each type, which must accompany the person, bearing a counterfeit, confusingly similar or restricted gray market trademark, provided that the article is for personal use and is not for sale.
This exemption may be granted not more than once every 30 days. The arriving passenger may retain one article of each type accompanying the person. For example, an arriving person who has three purses, whether each bears a different infringing trademark, or whether all three bear the same infringing trademark, is permitted only one purse. If the article imported under the personal exemption provision is sold within one year after the date of importation, the article or its value is subject to forfeiture."
As for buying fake stuff, from what I can see, you will get what you pay for, which is not very much for not very much. The fake stuff will probably not last long, the pens will break, the shirts may not wash well, etc. The watches will probably keep working, but a fake Rolex is so easy to spot (don't let anyone handle it, its lack of weight compared to a real one is the first give away, same with the Mt. Blanc pens), that I don't know why anyone would want to buy it. There is so much interesting stuff to buy in China in terms of handicrafts that buying fake Rolexes and Mt Blanc pens, unless you are like 22 years old, is just beyond my understanding. If you want to buy fakes, then buy the fake pearls in the Hongquio pearl market in Beijing, they at least look nice, wear well, have a nice feel and aren't trying to pass themselves off as a name brand.