I bought this sig and ava from Viper-WOH but I still see he has it for sale on his premade sig website.

Is it legal to sell the same sig to more than one person without telling them? I was wondering because I don't want someone with the same sig as me.

No it's not legal to do that
3. Once a sig is sold, it must be removed or tagged as sold, no image is to be sold twice.
Pulled from the premade signature gallery sticky in the sig/ava forums.
PM him about it, be nice..he just might not have gotten around to it, if he doesn't remove it PM Souforte about it.

btw, viper-woh is on the known ripper list :S

its a nice sig though =P