These pop up from time to time. The main issue is the use of trademarks and logos. The article indicates he was issued several cease and desist notices and didn't respond.
There are many in our hobby that walk a real fine line, and in my opinion even cross over it. You need to be careful with your wording, your image use, and what you are selling. Lucasfilm does not own the concept of an "illuminated saber" and their MK and Flashgun designs aren't owned either. But there are many designs, names, and logos that are. You need to be careful if you are selling. If you are respectful and respond properly to cease and desist letters you likely won't get sued.
These things are always a good reminder of the need to observe the law and walk wisely.
If we do these things the saber building community will be fine, in my opinion.