Trading without stop-loss is indeed very risky, especially if you are trading through internet, from home.
As a business practice, there is no need for placing stop-loss, if you are a confident risk taking regular trader.
If you are trading full-time from a broker terminal (through one of their terminals in their office), then you should keep an eagle eye on the price and volume constantly. Many times the prices pierce through stop-loss points (and thus our holding is wiped out) and comes back to normal in a single session. Like any other technology enabled gambling, the stock markets are prone to such manipulations on regular basis.
I have good experience of trading without placing stop-loss with a success rate of 58%, and I do not recommend trading without placing stop-loss points.
To sum it up, the onus is on you to take risk (or not), based on your exposure limits per session per broker.