illegal to crawl open source forum and post the threads in my forum?

is it illegal to crawl open source forum and then post the threads i crawled in my own forum?

if yes, what is not illegal to crawl?

cause there are a lot of crawling tutorials and classes you can download to crawl.

i want to know what they are good for?

From serverfault $pageUsers[$entry.posts[0].author].name

• Whether or not it is illegal shouldn't really matter. It is (In My Opinion) unethical, it's a form of plagiarism.

  Crawling can be used legitimately, for instance, to provide a near-to-you "backup" of a forum if for example, you are going to be somewhere with little or no internet connectivity and you want/need to read through the forum offline, or if you want to extract certain posts containing keywords that interest you and disregard the rest.

  My basic point is, don't do it unless you have the permission of the site owner, you provide it as a mirror (with the owner's permission) and don't pass it off as your own, or if you are going to be the only person using it (as per my example above)

  voretaq7 : +1: If you're going to be putting up your own forum try to generate your own content/discussions. In the long run it's more valuable for you and for the internet community.
  From Dan