Generally, one of the top questions I get asked from people who have never visited Thailand is: is it safe? They automatically assume that, because Thailand is still considered (by some sources) to be a third-world country, it must be at least a bit dangerous.
But my answer is always the same: In my few years in Thailand, I have never once felt unsafe anywhere in our outside of Bangkok... which is a lot more than can be said of various places I've lived in the US. I've always felt secure in Thailand.
My girlfriend and I were on the way back from a music venue in a taxi around midnight, and apparently our taxi driver changed lanes too quickly as we approached the well-known [traffic nightmare] Ratchayothin intersection and cut up the driver of a BMW.
It being a red light, the driver of this car jumped out, in the middle of the road, and started waving around something resembling a big iron bar, yelling at the taxi driver and hitting the car with his hand. When his accompanying lady in his passenger seat yelled something to the effect of "That other taxi is filming you," the crazed young Thai guy ran and started threatening the taxi next to us, waving around his iron and beating on the taxi's windows. He then ran back to ours, glaring at us in the back seat as I tried to calm myself and my girlfriend, shouted more, jumped back in his car, and sped off.
Then began the chase. Luckily, we were close to home, so we quickly paid our taxi driver, who used the opportunity to open his boot and pull out what looked like another large piece of metal, and he sped off with the other involved taxi to chase this lunatic. What's with Thai drivers carrying around big pieces of metal? I guess it's better than guns...
My point of all this is, no matter how safe you think you are, you've always got to watch out for crazy people. I have no doubt drugs were involved; this was a young guy driving a Beemer, so you know money wasn't an issue. I certainly hope no harm came to the taxi drivers.
Will my answer change about feeling safe in Thailand? Absolutely not; this is the first time anything of this nature has happened to me in Thailand, and obviously, crazy people aren't specific to Thailand. I've lived in places like Atlanta where these kinds of events are commonplace.
That said, I'd say that everyone should follow the advice most likely given to them as children: be careful, and stay safe!