Is it possible to identify someone elses web site as being of incorrect content and that it should either not appear in Google searches or at lease should not appear high up in the results. Is there some kind of categorisation that web sites have. I am particularly concerned about sites that have hacking and cracking information in them which I dont believe should be easily.
I think you have asked a great question, because you are probably seeing how easy it is to manipulate the search results from Google and other search engines. I would say that you cannot be 100% sure the website behind a particular link has been hacked. But Google, for example, used to employ an automatic checking service for every URL to determine it's rating, and would warn you before you actually click on the link. But you can sort of do the same thing. If you are concerned about a particular link, just copy and paste the URL into an online service that lets you view the HTTP headers. hxxp://www.rexswain.com/httpview.html When you do this, the webpage comes up but it's all text. So you can tell for yourself if the website looks okay or contains malicious content. I don't do this for every URL, but I do for those that I am suspicious about. You can probably do the same type of thing with a toolbar utility or similar software program but I would highly recommend viewing HTTP headers before following the hyperlink, if you have reasons to be concerned. Good luck.
If you think a site that do not deserve to rank high is appearing in SERPs, then you should report that to Google: google.com/contact/spamreport.html
But why should we need to report it.. Is there any other way for Google to identify these type of sites.