It isn't necessarily illegal (though it can be), but it is certainly frowned upon. Especially if someone just goes around making posts that are all plagiarized from someone else, giving the impression that he is the author. When you do something like that it is appropriate to cite a source. Not aiming this at Dangerous Incorporated (for all I know, he could be the blogger at /film, though probably not), but the whole typical lack of citation is an example of how the internet is turning everyone into Neanderthals. Suddenly everyone is a journalist with their own blog page or whatever other fancy names they give them, and they feel free to rip off the ideas of others and claim them as their own, or at least not claim anything of them and allow reader's to assume they are their own.

I remember in Sluggo's SW Valetine contest a few years ago, a contestant came up with some really well thought out Valetines, which it turned out he stole from another site. When someone pointed it out, he calmly replied, "The rules never said it had to be your own work, so they still count as my entries". Pah! Stuff like that shouldn't have to be explained. Neanderthals. I swear, evolutionary regression has begun.