i'm an administrator of an Instagram page in which I make posts about drawings and covers related to comics. Obviously I am not the author of these drawings but I always add in the description the name of the artist if I know him. My community is growing steadily and I am afraid that when I reach a higher number it will be reviewed by Instagram and close my page. How could I do to know if I am violating any law without putting my community at risk?
Obviously I am not the author of these drawings...
If you are posting on Instagram creative material by other artists - drawings, photographs, illustrations - that you did not yourself create, then you are 1) violating Instagrams Terms of Service, and 2) infringing on the copyright of the artists of that work.
1) The Instagram Terms of Service says (emphasis mine):
You are clearly in violation of the Terms of Service. Your "community" is not at risk; they did not post the material. But you are at risk of Instagram closing your page.
But, most importantly, 2) you are also at risk of being the subject of a lawsuit by the artists for infringing on their copyright. All the artist (or creative company) needs to do is see their work on your site, and they can send a takedown notice to Instagram claiming copyright infringement, and could serve you papers for a civil court action.
Naming the artist makes no difference; you do not have permission or a license to post their work. The number of visitors or members of your community makes no difference; posting one image you don't own and one other person viewing it on Instagram is a copyright violation.
Even if you have only used a small part of a whole work by the artist, you may not prevail using a Fair Use (Fair Use - U.S. Copyright Office) defense in court.
You are violating copyright law if your posts include direct copies of the material, and not if you link to the graphics hosted elsewhere, or don't even have pictures. However, you you have permission from the copyright holder to directly post the drawings, that is not a violation. Otherwise, you are free to say whatever you want about the art work, at least under US law (because of the First Amendment); there are countries where you have to be careful what you say.
Instagram might decide to take action against you for violating their terms of service. That includes doing anything illegal (copyright violation); it also includes behavior rules such as Instagram Platform Policy and Instagram Community Guidelines. The latter includes rules of the kind "be nice". If you engage in an action which they decide is contrary to their TOS, they can terminate your account. You do retain the right to resolve disputes via binding arbitration.
If these images are accompanied by critical commentary on the images, they might be defensible under Fair Use (under US law). This might avoid a judgement against you f you were sued for copyright infringelment, but is in no way guaranteed.
However, Instagram may well not want to try to evaluate whether your copying falls under a fair use defense or not. If they receive a takedown notice, or if your page somehow comes to their attention, they may close your page for apparent copyright isuses without waiting for a court case. (In fact if they get a valid DMCA takedown notice, they are required (in the US) to act quickly unless they wish to become a party to any future lawsuit against you, which they won't want.)
If these images are posted online by the artists or publishers, you could simply link to them, along with your comments. That is much less likely to cause any problems with Instagram, or any possibly lawsuits.
You may be able to get the artists or publishers to give you permission to post these images, perhaps in a limited resolution or size. That should avoid any copyright issue. But there is no guarantee that you will get any such permission. No one is required to give it to you. They can demand a fee, or just say no, as they please.