This thread on The Replica Collector brings up a good point: Customs services around the world are becoming more aware of replica watches each day. Don't tempt fate by ordering a large number of watches at a time from any one vendor. The larger the purchase the more suspicious. After all, most people don't order a dozen Rolex watches for "personal use." The moral here: buy replica watches one at a time, not in bulk.

European (and Canadian) customs seem to be the tightest. There are fewer US buyers complaining about replica watches being seized by customs as far as I can see.

My suggestion is first of all, don't buy replicas for Christmas presents. While it might seem cool to give Dad a fake Rolex for the holidays remember they don't have the background to understand the limitations and potential risks wearing a replica entails. While no one will be arrested for wearing a replica Rolex, there is a strong possibility that if they get called out about it (someone "spots" it) you'll be the one taking the blame.

To me owning a replica watch is a personal choice of people who understand they're buying a piece of potentially flawed merchandise that they're willing to accept the risk of it breaking/getting water in it/being spotted as fake. These are things that as you make the purchase you personally are willing to accept. Gifting a watch like this to someone who hasn't made that commitment can lead to trouble down the road.