Scraping content and/or files is a serious no no. It's paramount to plagerism and that's against the law just about everywhere around the world.
If you're just wanting to see how some one did something at thier site, 9 times out of 10 just asking gets a friendly answer. I don't mind sharing how I did something at mine. But if you come in and steal my custom code, I'll know.
As for content, again if you ask you'll most likely get permission to use as long as you give credit to who it belongs to. But be prepared to take no for an answer...