As with all such programs, it is best to conduct experiments to see if the results are what you expect. With Windows, many times files are located in multiple locations, as well as temp files that contain portions or complete versions of files. Just because you erase a file in one location does not mean that it was erased remnants in all locations. Then there are the ISP log files that show when and where your IP was recorded, the websites visited, and the files downloaded. So your tracks are left in many places.
That said, Eraser does what it is advertised to do. It will overwrite files and freespace, according to whatever method you choose from the list. The files are not recoverable afterwards, unless recovered from areas that were not overwritten (and it is up to the user to know where and what to overwrite). I know this because I have tested it in a variety of ways using forensic file recovery tools.
However, if you believe that you can do what you like on the Internet and trust one program to deliver you from prosecution, you are probably mistaken. Ignorance, foolhardiness, and mistakes are rampant among many who feel they are safe on the Internet. Heck, just look at evening TV to see how many guys fall into "stings", sometimes repeatedly. Their addictions lead them to do exceedingly stupid things, usually starting with the Internet.
