Cloning a website is reproducing the functionality of the site being cloned. For example, Fiverr.com is a micro jobs site, charging only 5 dollars. There are plenty of clones with twists on fiverr, for example: Gigbucks, tenbux, 10den, etc. These can be in a different niche, charge a different rate, and have a different flow to them. In terms of getting the site "removed" as long as there is no copyright infringement, aka passing the website off as say "fiverrr.com" or claiming to be the same company, you're usually in the clear. I am not a lawyer, but the basis is that if the code is written from scratch (not copied from the source), there can be no claims to intellectual property.
There are popular clones of ebay, fiverr, etsy, adfly, groupon, etc - with entire companies focused on providing the cloned scripts to a userbase.
Hope that helps.