When Laurel Burch passed away, her heirs began to aggressively go after folks who were selling things made with her fabric. When you get attacked by lawyers, most folks cave in. When someone took the heirs to court, they buckled.
Patterns are another area of murky copyright. Some makers claim you cannot sell or enter in a show anything made from a pattern you legally purchased -- that is also not true. You can't sell the pattern, but what you make from it simply needs to give credit to the designer,
Here is a link that should help understand that as well:
http://www.tabberone.com/Trademarks/...Patterns.shtml