Yeah, not buying it.
Honestly I can't see a single good reason to do it, and the methods of doing so are all flawed, better to just not bother.
I'm selling downloadable products (GB in size, this product took me months and months of development) and providing download links to customers. I need to mask the location of the links so that they cannot be distributed.
Perhaps if you cannot see a "single good reason to do it" you should try gaining a better imagination, or at least ask the poster "why" before jumping to conclusions.
The reason I posted "I have a legit reason to ask" is because I've been google-searching and came across many forum posts with the same question, and same rude answers "You shouldn't be so dishonest. Don't do it".
If it wasn't for the dis-honest nature of the human race, I wouldn't have to mask the download links, but sadly, in the month of december, my product links (although I'm changing them manually as often as I can), have already been pirated and I've had over £1075 in excess bandwidth charges due to non-paying users downloading the files.
I've already got a programmer working on the system, but it won't be up and running for a few weeks, so I need to mask the download links in the mean time.
So please, in future, don't presume.