Bicycles were introduced in the late 19th century in Europe, and by the early 21st century, more than 1 billion were in existence at a given time. These numbers far exceed the number of cars, both in total and ranked by the number of individual models produced. They are the principal means of transportation in many regions. They also provide a popular form of recreation, and have been adapted for use as children's toys, general fitness, military and police applications, courier services, bicycle racing and bicycle stunts.
Legislative changes in 2012 significantly altered the classification and regulatory structure for e-bikes. The general effect was to establish electric-assisted bicycles as a subset of bicycles and regulate e-bikes in roughly the same manner as bicycles instead of other motorized devices with two (or three) wheels. Laws 2012, ch. 287, art. 3, §§ 15-17, 21, 23-26, 30, 32-33, and 41. The 2012 Legislature also modified and clarified regulation of e-bikes on bike paths and trails. Laws 2012, ch. 287, art. 4, §§ 1-4, 20.
It appears Tennessee has not passed any legislation that applies to electric bicycles. Some people think the laws pertaining to a Motorized Bicycle should be used for an electric bicycle. However, a Motorized bicycle would be a gasoline powered device per state law as it is defined as "means a vehicle with two (2) or three (3) wheels, an automatic transmission, and a motor with a cylinder capacity not exceeding fifty cubic centimeters (50cc) which produces no more than two (2) brake horsepower and is capable of propelling the vehicle at a maximum design speed of no more than thirty miles per hour (30 mph) on level ground." 
During nighttime operation, the bicycle must be equipped with a front headlamp, a rear-facing red reflector, and reflectors on the front and rear of pedals, and the bicycle or rider must have reflective surfaces on each side. Minn. Stat. §169.222, subd. 6. An electric-assisted bicycle can be equipped with a front-facing headlamp that emits a flashing white light, a rear-facing lamp that has a flashing red light, or both. The bicycle can carry studded tires designed for traction (such as in snowy or icy conditions).
Under New Jersey law a motorized bicycle is "a pedal bicycle having a helper motor characterized in that either the maximum piston displacement is less than 50 cc, the motor is rated at no more than 1.5 brake horsepower, or it is powered by an electric drive motor and the bicycle is capable of a maximum speed of no more than 25 miles per hour on a flat surface." This would include E-bikes, meaning they must be titled and registered. However, only Mopeds approved by Motor Vehicle Services can be titled and registered.
Regulations appear to deal with Bicycles with helper motors. No person shall ride a bicycle with a helper motor unless that person holds a valid motor vehicle operator's license. No person shall operate a bicycle with a helper motor at a rate of speed exceeding thirty miles per hour; nor shall any bicycle with a helper motor be operated on any sidewalk, limited access highway or turnpike. Driver's licence is required except if a special permit is obtained by havnig a doctor fill out a certificate and shows they are able to drive the bike with and without the motor assisting.
Both the Stromer and the Stoeckli are very nice looking designs and easy to handle. Reliability for both does not seem to be up to Swiss standards, e.g. some of the 2012 Stöcklis seem to have bad contacts. However, as of 2013, most of these problems should be fixed. The Cube got criticized for its battery/saddle system, but this has probably been fixed in more recent edition and it has less "punch" then the other's since the motor is smaller (324W?). I don't know about the BH Neo Nitro. Given the relatively low price of the BH Nitro, it may be the best buy in this category if you plan to cover smaller distances (the battery is limited to 9Ah, and Spain's industry does need some help ;) Anyhow, all of these models come with a variety of motors and country-specific modifications. E.g. in France, the BH Nitro comes with a 350W motor and is electronically limited to 25km/h, whereas in Switzerland you either can get a 500W - 45 km/h version or a 250W? - 25km/h version.
Around the turn of the 20th century, bicycles reduced crowding in inner-city tenements by allowing workers to commute from more spacious dwellings in the suburbs. They also reduced dependence on horses. Bicycles allowed people to travel for leisure into the country, since bicycles were three times as energy efficient as walking and three to four times as fast.
On the other hand, the battery doesn’t lock into the bike, which means you can’t just leave it on your bike when you park at the bike rack. Anyone could walk by and simply remove your battery. That seems like an oversight to me, though perhaps the designers assumed that such a small battery would just be easy to take with you. And it is. My wife could probably lose this battery in her purse.