Screen Scraping Rules?
nostrademons: AFAIK (and IANAL), information on the web is public but copyrighted.  That means that you can read all the data you want (though it's polite to obey robots.txt), but if you redistribute it you have to obey the normal copyright provisions, i.e. you can only take what's considered "fair use".  Fair use depends upon a lot of factors - how much of the original work are you redistributing, how much of the re-aggregated work does it compose, is it commercial or non-commercial, and are you harming the original content owner's business model?  Talk to a lawyer for specifics; there are a lot of grey lines, and if you're close to one you really need a professional to tell you where the line is.You can't copyright facts, so the mere act of taking data off the web is not illegal.  For example, if you came up with an algorithm that could extract stock prices off webpages and then used that to put together a stock chart, you're well within your rights to publish that.  But if you extracted the text from those pages and then put up a news article with each inflection point, you may have a legal problem, depending on how much of the text you used and a bunch of other factors.  Again, talk to a lawyer for specifics.