While I agree that published manga, especially ones that either are, or are planning to be released in the west are a big no-no, especially from sites that use obsessive amounts of ads to generate revenue for illegal content.
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The main issue with all of the larger sites is they won't take down licensed content, this puts unnecessary pressure on local companies, while most can support themselves (but shouldn't have to) more niche titles either don't get picked up, or canceled.. Best example would be
Translator Discusses "Wandering Son" Manga Status
I can't name any sites that actively take down licensed content
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Although my opinion does (kinda) change when it comes to Doujin material, Most of the books self-published by Doujin artists rarely get releases in America/UK. The only exception from my understanding would be the (now defunct as of June 2016)
DoujinPress.com – Printing and Buying Service for Doujinshi who did get some English translated Doujin in print.
While I personally buy a number of Doujin items from groups that I follow on sites like Pixiv, being Japanese only and pretty darn costly even through sites like Melon Books, its difficult to justify the cost vs what you physically get.
So please Don't get me wrong, I think these artists 100% deserve to be paid for the work they have done but sometimes it just not justifiable or even possible to buy Doujin releases
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After saying all that about Doujins,, I don't agree with Doujin sites that have things like Official Rips, I don't/wont use them as once again, I don't agree with people blatantly stealing content like this... There is a vast difference (in my eyes at least) between someone translating a doujin and someone ripping content off official, and even fan translators w/out knowledge
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On the other side of things, Fan Translations can, and are used in the production of official release, DMP are working with the group behind the translation for kodomo no jikan and Yuri-Ism (A well know Yuri Group) has also released official translations
So my main hate is for
1) Sites that don't take down Licensed content
2) Sites that use a lot of Advertisement for Revenue from Stolen Content
3) Sites that go out of their way to host Rips