tl;dr Please stop posting answers that are just copied out of Wikipedia or some random blog. If you see these things and they don't cite a source, flag (either "very low quality" or "other" and specify that the post is plagiarized) and downvote. Even if they do cite a source, consider downvoting.
Islam.SE has had a problem with people copying and pasting answers from elsewhere. This apparently happens on other Islam-related forums. There is an interesting parallel here, in that exactly the same thing happens on Hinduism-related forums, and now it's happening on this site, too. I hope that bothers you.
Rather than repeating everything they've said, let me just point you to their meta site: The copy-paste issue, revisited.
Please read that post and take it to heart. I have been spending quite a bit of time since this site launched editing posts. Far too many of the edits I've made have been to add citations to plagiarized content, and blockquoting content that cites a source but fails to point out that the whole text is just copy-pasted. This is tiring and unrewarding, and I simply don't want to have to keep doing this.
I have already begun aggressively dealing with these posts by downvoting them and flagging them as very low quality (because they are analogous to very-low-quality "link-only answers" at Stack Overflow), and I recommend that you all do the same.