I agree these get great videos of trains. I don't agree with those that believe all operators will fly their sUAS responsibly.
As a 5,000 plus hour pilot, currently flying with the Civil Air Patrol, I agree with Rich. I believe it is just a matter of time before one of these small unmanned aircraft system (sUAS), or drone, with camera causes serious damage, injury, or death due to the operator trying to get the best pictures. No license is require if the sUAS is less than 55 lbs and not used for profit, and I assure you a 54 lb sUAS will do a lot of damage. Nearly all R/C aircraft need skill to fly and usually needs to be close enough for the operator to know what the aircraft is doing, not so a sUAS. A sUAS can be flown by most anyone, from anywhere, and GPS controlled ones can be flown out of sight of the operator. And don't talk to me about how everyone will follow the rules; we already know sUSA operators don't follow them primarily because the operator is in no risk of getting hurt. While a few airplane pilots have done stupid stuff, we follow the rules for the safety of our passengers and ourselves. A reporter at the LA Drone Show stated there are more sUAS in the air than aircraft. This should concern you.
That said, CAP is starting to use sUAS in our search and rescue work. However, the FAA, local law enforcement, the incident commander, and others are coordinated with before flight. For training at the airport, we will have constant radio contact with aircraft in the area so they know were we are at all times, not just that we are in the vicinity.