TIME TO RESURRECT A THREAD!

So! Let me explain what I'm doing here.

If people aren't aware, an editor for IGN recently got caught with their pants down. What do I mean? Well, they plagiarised almost word-for-word, a review of an up-and-coming indie game from a (then) smaller youtuber. And I'm talking they copy-pasted the transcript for the victim's review, changed a few words in an attempt to cover it all up, and put it into their written and video review of the game. Of course, the youtuber in question caught this writer since they were an avid visitor of IGN. They compiled all the evidence in a side-by-side video, and the rest snowballed from there. IGN fired the writer, and the video and written reviews were taken down.

So why am I bringing this up? Because this incident sparked a question in my head.

How do you determine plagiarism of writing/words? Sometimes, it's blatant like the case I presented above, but other times it can get VERY tricky. So how does one spot such a thing in the first place?