As a person who has a degree in Graphic Design and Advertising/Marketing, I think its safe for me to say this, now I can totally understand someone getting angry when their authentic and original work being stolen, or taken without credit. Or someone passing it off as their own, or especially when someone else takes your stuff and trys to make money off of it. I completely understand getting pissed about that.
However, if someone just takes your shit to use as a fucking icon, and they don't ask, or don't credit, don't get pissed about it, especially if the icon isn't your original piece of work, I mean common, you yourself stole the base image to begin with, without the express written consent or any payment to the original copyright holder, so If I take your shit, and don't comment, or don't credit, but its not fully your original work, don't get pissed, cause you did the same shit if not worse by taking the original piece as a base image, I don't care if you changed the tint, or the hue, or the brightness, thats fucking child's play, ooo, you added a fucking word to an image of Darth Vader, yeah, thats totally your official and original work, it took you all of two seconds to make that fucking image, you don't even deserve credit for it.
Now, people who produce their own, original, from scratch authentic, art, and photos, thats another story, and definitely deserves credit. In the mean time, I don't care who you are, or who you know in the online world, if your not producing original shit, don't get mad when someone takes your shit and uses it, and if it matters that much to you that someone took your half ass work shit, that was not originally yours in the first fucking place, then maybe you shouldn't post that shit all over the internet for it to get taken!