They seem mostly searching ways not to pay. Maybe the Internet ad-system doesn't work that much for them, in fact...
So what will be the reason next time? People kissing in pics (maybe not married!) or brown dogs or cats appearing near the cars? By the way, shouldn't weasel1984's avatar be censured (concealed nudity)? And mine, for possible bestiality?
I think this will never end...

You said there is a need for at least 600 €/850 $ per year just for the server. There is indeed less expensive offers, depending of course of the needs of the database.
But did anyone ask if we are not enough willing contributors who would agree to contribute with 10 €/15 $ (or more) per year? Why not make a kind of foundation or association that could recover money for it? In my mind, this would be more "professional" than having ads, even if these ones are aimed to cars or whatsoever we and the other visitors are supposed to have interest in.

I give that amount almost every year to the Wikimedia Foundation. I would do it with pleasure for the IMCDb too, as I do believe this website is worth it. But don't ask me to deactivate my browser anti-ad system, as I don't want to be bored by ads when visiting a website, all the more when I like it and try to contribute to it. And also because I don't believe in this business model.
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Talking about "serious and professional" approach and public recognition for the quality of the IMCDb website: the main reaction when facing female nudity should be the same as when it concerns male one. Or at least less frenzied. It could be otherwise really easy to call the IMCDb website a "teenager fans website"...