Should I put my username?

Okay, I wanted to ask you guys if you think I should post my username in my works (ecard and Iphone walls) since now it have happened to me twice that friends find my work in tumbrl not even with a original link from the work and or giving credit to the person who made it. I didn't like it but should I? It kind of pissed me off seeing my work like that.

update*

I guess I will be putting my username in all my works now, I'll try not to make it very visible :I my older works gonna have to be without username cuz I'm too lazy to change it -__- lol

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