So, I saw on another wiki that someone had copy-pasted entire articles (about 20 whole articles) from a .net site, like the wikis that are not on Wikia. The information wasn't paraphrased, and no credit was given. Is this allowed?
Hi ChloeKnight. No one here is actually in a position to decide whether that's allowed or not, since we're not empowered to make legal judgments. If the copyright holder of the information objects to the use of the content on Wikia, they are welcome to send us a DMCA takedown notice.
Its unethical at the least. Those people worked hard for their work, and the Berne Convention gives them the write to create anything and for their wiki's license to be obeyed. Assuming the other wikis are copyleft like Wikia, a link in the bottom of the article is required to the orignal source, along with a list of authors (page history basically) and a link to the relevant license. If not, its probably a copyright violation because releasing your work on a license for free still means its copyrighted with allowances made for the license's free aspects (if this makes sense).
Its like online free services that usually state that a transaction of no monetary value is made (= free) in legal essence when you use their service, and you promise to abide by its Terms and Conditions in return for your use. Oh yeah, plaigarism is not allowed in the T&C either under the arguments of "online conduct", "submitting licensable content under CC-BY-SA". Hope this may answer your question.
While we are not empowered to make legal judgements as Brandon Rhea said, we are in the ability to control what we submit and actually write it ourselves. Most to all content has an original source anyway (One Piece Wiki uses the titular manga, Fast and Furious Wiki uses the franchise' movie dialogue/transcripts, etc). So realistically, its a case of giving a damn as opposed to just lazing about and copypasting other people's work.
PS: As I highly suspected when reading the full Creative Commons license, it is very possible to score a copyright violation even if it is a free license. You can go to court and pay damages for ripping off "free" content and monetizing it.
Also, the threat of legal action is quite real in the case of plaigarism, though most wikis have their hands tied when such behaviour occurs outside of Wikia and Wikimedia domains who are willing to both proactively retract content and also defend the fair submissions of their users legally when there is a copyright troll.