UPDATE 2: Good news!! First of all, I got a reply from the Japan Expo staff:

"Thanks for your e-mail. We were not aware of this situation before your contact and would like to tell you that we totally support your action. Neither Japan Expo nor Sefa Event would accept to be associated to plagiarism or bootleg products.

Most of the staff working on the festival are employed for the 4 days only. So, they are not able to bring you suitable reply. In that case, our advice is to go directly to the Exhibitors Desk where you can talk directly to one person in charge of the exhibitors.

We have already contacted the exhibitors who were selling these posters to get some explanation and asked them to get in touch with you. If within 15 days, you do not have any feedback from the exhibitors, please contact us. We will give you their contact details directly to fix the situation.

Again, we do appreciate your action and wait for the feedback of the exhibitors."

Positive feedback! I'm glad JE staff is taking this seriously.

I also was contacted by David Heim, organizer of the swiss animecon Polymanga. He did business with AniPopGam before and upon seeing what happened at JE, he contacted them upon *Qinni's and my behalf. AnipopGam replied the following:

"I have investigate the issue you told me last week. I am 100% confirmed that those Chinese manufacturers downloaded these 2 art images on-line since what these 2 artists drew are we so call fan art not original art. I think that is the reason why these manufacturers think it is OK to copy them. I can promise you that everybody in the convention who sell any products based on these 2 images has no idea what is going on out there. I think our thinking is it is not exact from the anime series Black Shooter Star. Maybe, the manufacturers just created the products have those images designed by their own artists.

The following is which I have been doing:

1. Notify all my dealer friends not to sell any types of products having these 2 images. So far, everybody I know is very much agreeing with me except MangaX.

2. I have contacted my source in China that don't even bother to sell me anything like that in the future since I will not buy it. I have educate them that copying the fan art is not Ok either. And, I will carefully check all of the images on the poster purchase from now on. I will stop any similar situation happening again.

3. I have already destroyed all of the posters which I think are related to their art works."

Moral of the story: Even when it seems hopeless, it's worth spreading the word when such things happen. You might recieve help from people you least expect it from. ^^

Again, thank you all for your feedback and advice! If not for the uproar of comments ushering me towards stepping up, I might not have done anything...so really, thanks, everyone!

I'd also like to personally thank and David Heim for their help.

*****

UPDATE:
First of all, thank you everyone for your support and feedback. I read them all and considered them.

For now I took the following action: I sent a direct e-mail to the organizer of the Artists' Alley of Japan Expo, explained them what happened, sent them proof and asked them to take action. I'm still waiting for a reply.
I also might receive another contact email soon (for Japan Expo staff) - as soon as that happens, I'll email them as well.

Also, I was contacted by~Shonbori who attended a convention in Memphis, Tennessee (USA) and again, saw my artwork (same) for sale: [link]
The seller didn't have a company name and insisted he bought the posters wholesale.
~Shonbori contacted the convention staff, explained them what happened, showed them my journal as proof, and the convention staff TOOK ACTION, agreeing that the seller should be banned from selling all of the posters.

Looks like with enough word out there, this can be - if not even entirely stopped, then at least - restrained.

With that said, I would like to ask everyone who might notice this artwork of mine (or any other for that matter...) sold as a poster at their local convention, please contact your convention staff, show them my journal and ask them to ban the seller from selling those posters.

Again: I didn't give permission to anyone to sell my artwork as posters anywhere. If I ever consigned anyone to do such a thing for me, I'd definitely make a public announcement about it so people would know.

Thank you all for the support! orz

*****

Thanks to a couple of fellow artists (namely *charln and ~kyara17 ) it was brought to my attention that my artwork has been stolen, printed and sold as a poster at a booth at this year's Japan Expo.

Artwork in question is this:


~kyara17 provided me with photos (click to enlarge!):


The booth was known as "AniPopGam 2", but I was told that the store itself that sold the stuff is called "MangaX".


My artwork to the left, along with another 2 obviously stolen fanart posters right next to it.

And just as I thought, other deviant artists have been ripped off too, for example who also wrote about it in her journal: [link]

*charln told me that she tried talking to both the booth staff and some Japan Expo organizers but with no luck: the booth staff of course pretended not to know anything about it, and the Japan Expo staff (to my surprise) said they can't do anything about it. ...why? Isn't it their job to keep such things from happening? I attended Japan Expo in 2009 and 2010 and I clearly remember there being such a rule as "selling bootleg/piracy merchandise is strickly prohibited".

And honestly, I think if I myself would've been present this time, even I, as the original creator of said artwork, couldn't have done anything because Japan Expo staff isn't doing anything even when approached with a clear example.

I don't have money for a lawyer or lawsuit, so that's out of question. I'd be more than happy if there could be a way to ban this booth/store from selling at Japan Expo ever again. I'm thinking of contacting the Japan Expo staff through email or something but I'm not sure...Contacting the store seems pointless to me. I don't think that threats of a possible lawsuit would make them stop what they are doing either. And asking them nicely would be even more pointless, they would just turn a blind eye on the whole thing and pretend to be innocent - maybe even start pointing at the Asian pritnshops that provided them with the merchendise to begin with. And reaching those printshops...is clearly impossible for someone like me.

it still leaves me dumbstruck that someone would steal artwork from Japan Expo attendies...only to go back to the scene of crime and sell what they have stolen there? That's pretty dumb if you ask me.

But honestly...can anyone give any advice on this? Has this ever happened to any of you? How did you tackle the problem?
How can an artist PROVE their right to their own artwork (besides lawsuit and watermarks)?