There are quite a few stories on here with the attribute of 'inspired by cmsix'
Again, if you lift the whole basic plot, with few changes, then even if you use your own words, you're dancing very close to legal jeopardy. However, if you write a story that's similar, dealing with the same themes in a similar situations, then you're generally in the clear.
It's akin to when someone reads a do-over story and thinks 'Damn, I could write something better than that!' No one can copyright concepts. They didn't 'invent' the do-over concept, they simply borrowed from others before them. However, what distinguishes authors is what they can do with a given subject. Copying text, characters or plot points is just plain lazy writing, as you're admitting that you really don't care about coming up with you own story.
But, if you take a similar situation, add unique characters, give them real, engaging personalities and present them with new challenges, you're well on your way to create great (or at least really good) art.
Once again, it's mostly a matter of personal pride. Do you see yourself as a 'creator', or do you merely want to 'get something' with the least effort imaginable.
Thieves are notoriously lazy, which is why you have so little crime when the weather turns, since the criminals all stay indoors because it's too damn hard going out. It's also why you have so few 'novel' types of master criminals, because they simply don't put that much thought into anything they do. They just grab whatever they can reach whenever the opportunity presents itself.
The few times someone does add an 'inspired by', it's largely where they 'borrow' the basic plot up to a particular point, and then branch out from there. In that case, it's like fan fiction, it's OK, but only as long as the original author doesn't object and report your for stealing their work.
In short, writing is damn hard work. There really aren't any shortcuts. In porn, in whichever variety, you can squeeze by with stereotypical or cardboard characters and no one will really care, but if you write more than a couple of chapters, people are going to want more depth, even if it's merely a stroke story. They want to know what attracts the one person to the other, what they're getting out of the relationship, how long it'll last, whether the characters are being honest with each other.
Those looking for easy ways to write had better consider working in an third-world telemarketing firm.