I don't think you'd be immune to the risk by practicing cautious dwnloading. This is why, after learning about this risk, I don't download files off of limewire anymore. Mainly I just go on to browse what other people have. Honestly, if you take a screenshot of the file names that pop up when you type in some words, it shows the obvious implied content.

I don't really see why law enforcement goes after purposeful downloads either, it's data, go after the people making the stuff.