Hi Portee!
I have been one of those 'idiots' that got hosed on a margin call a couple of times in the past. It is no picnic when the market swings violently and you suddenly realize 20% losses in just a couple of trading sessions. However, I can also state that I have earned huge profits during the last few years by tapping into margin, and then taking profits later to pay it off while keeping the remaining 'free' shares. In fact, I bought some KXL on margin today. Where the strategy gets you into trouble is if you go too deep into margin and are thus vulnerable to big corrections. Its all part of the learning process. Another thing worth noting is that your total margin available is based on all the stocks you own, and even if you are leveraged up on blue chip stocks, banks, etc. you can still get pounded and get a margin call. At that point you sell whatever has liquidity and what you can get a decent bid on. So those selling KXL may have been hosed due to an overweight position in NG, or BMO, or something else that was regarded as less speculative.
cheers!
mike