Bikes like these are light, so easy to steal obviously.
To keep someone from riding off with it, when you lock it up to something (heavy steel preferably), run the chain/cable through the front wheel and frame, and the back wheel if possible. This will make it tougher for someone to ride off with it (also having a quick-release seat helps that too). As for the guys with trucks, really all you can do is use a heavy duty lock on a heavy duty something-er-other to lock it up.
I'm lucky, we have an indoor bike rack in our warehouse, so I can use that. Hopefully they don't pitch a fit about my motor though....