Social forces are any human created ways of doing things that influence, pressure, or force people to behave, interact with others, and think in specified ways. Social forces are considered remote and impersonal because mostly people have no hand in creating them, nor do they know those who did. People can embrace social forces, be swept along or bypassed by them, and most importantly challenge them.
Social force can be understood with many examples such as the usage of the universal credit card to defer payment for products and services. This human-created invention became a "social force" that encouraged unprecedented numbers of people to spend money ahead of their earnings. While credit cards afforded those who could acquire them opportunities to delay paying for things they needed or wanted, it took special effort, discipline, and/or an advantaged position in life to resist using them.
In late 80s in USA another social force emerged when banks moved away from a system in which they had made loans and issued credit cards to borrowers only after doing careful credit checks documenting real income, job stability, and credit history. Banks shifted to a system in which they knowingly issued loans to those with poor credit histories, gave loans larger than many borrowers could realistically afford to repay, and extended spending limits on credit cards to levels that many consumers found hard to resist.
The cellphone is a technology that was invented to free them from landline phones and to allow them to communicate with others while on the move. Undoubtedly this social force has changed the way people communicate.