creating or pilfering ingredients?

Just got my computer running after a week and still do not have all the software loaded.  I have noticed from seeing other sites that a lot of the raw recipe ingredients from various sites are looking similar lately.  Makes me wonder who actually created the original.  It's really easy to take someones ideas and change a few things to make it look like your creation.  Thing is, does that make you a thief or someone who can adapt a recipe to fit your style?  A lot of the raw food creations are taken from a cooked version and made to taste similar to the cooked "comfort" foods.  There are recipes out there whether raw or cooked that just don't taste the way you want them to so you change this and that and add this or that to make a version that is delicious to your taste buds.   Where does that line get drawn?