Fifteen years ago people could not imagine that it would be possible to communicate with people at the other end of the world twenty-four hours per day, sevens days per week for free. Before the Internet was available to the major part of the population of the world, the possibilities to communicate with relatives or friends and possibilities to meet people from other countries all over the world were limited or even impossible. Telephone and postal services were and are accessible to almost all the people all over the world, however, one must admit that the speed and quality of these services were not and actually are not good enough to satisfy needs of normal communication. Internet offers speed, usually quality, possibility to share music and photos, possibility to contact anybody at any time. It seems that the Internet is the ideal way of communication, which additionally offers thousands of options in order to make the communication sound and look perfect. …