Regarding copyrights and Google penalties

I have a brief question. I am developing a site that includes many pages of (ostensibly) public domain material among its content. Due to the number of pages involved, it seems inevitable that occasionally I will discover that a particular page or series of pages is copyrighted after all as the copyright owner reports this either to my host or to Google.

I assume that when the latter occurs, Google will remove the offending page/pages from the index. My question is, what of ranking penalties? And if the penalty is based upon the number of occurences, how many does it take to receive a penalty from Google on the site itself which would affect the overal traffic?

Also, when the former occurs, does the host typically request that you remove the material or do they shut down the site entirely?

I realize that this is a noobie question, and I thank you in advance for any help which you see fit to provide.

If you have a set of content and a copy of it exists elsewhere on the web, Google doesn't have to be alerted to the issue by a third-party; they'll know automatically. That said, these pages of yours will probably get de-indexed but I've never seen an entire site being penalized for having some duplicate content. If you're doing anything spammy, then you might raise a flag but otherwise, I don't think it's going to be a huge issue (but I'm not 100% certain; wait for more opinions).

What action your host will take if someone reports you is impossible to predict. Most web hosts contact their customers before taking any severe action but then again, there are ones who don't. You might want to read their TOS, and maybe search Google to see if you can dig anything up from the past (customers complaining about your host terminating service etc).

Nice post, also I have observed that it is not actually a sort of penalty but the page gets filtered.

Google tries to find authoritative content is through backlinks. If two pages are exactly the same but one is from other domain. Google tries to find the original source, in my experience, a particular document with higher number of backlinks and an older page is more authoritative hence it is the original so it will show in Google results. The other one is labeled as unimportant and gets filtered in search.

Your best bet is to file as a Designated Agent under Title II of DMCA.

This way so long as you remove any potentially offending content your domain is protected from all infringement claims.