People do it all of the time for various reasons that I'm not saying. I wouldn't suggest that you do it on your main internet line. People usually want a dedicated DSL line (non-fiber optic) so they can reset the connection and get a new IP address. With that said, if you did it to your main internet line, then you'd lose internet connection often as they cycled it for a new IP address. When my phone company finally straightens out my second line, so it doesn't drop internet for days at a time, I'll have my rDSL up for someone to use. "r" in rDSL just means remote DSL, basically a dedicated computer connected to a dedicated DSL line and they connect to to the computer with some remote connection software, like TeamViewer.