Traveling To Warnock's Dilemma and Beyond: The Fermi Paradox

(2.3.3) The Fermi paradox is a paradox proposed by physicist Enrico Fermi that questions the probability of finding intelligent extraterrestrial life. More specifically, it deals with attempts to answer one of the most profound questions of all time: "Are we (human beings) the only technologically advanced civilization in the Universe?". The paradox was formulated in response to the Drake equation for estimating the number of extraterrestrial civilizations with which we might come in contact. Subject to the values inserted into this formula, the Drake equation seems to imply that we should not expect such contact to be extremely rare.
Isn't the process of broadcasting (whatever it is that we broadcast to potential aliens) simply another variation of tweeting to the universe and hoping to get a response to our query? If we don't receive a response to our broadcast, what does the 'non-response' indicate?
Steven Hawking thought about the Fermi Paradox and suggested that we may have not encountered life because of the following:
- The probability of life appearing is very low.
- The probability of life is reasonable but the probability of intelligence is low.
- The probability of evolving to our present state is reasonable, but then civilization destroys itself.
- There is other intelligent life in the galaxy, but it has not bothered to come here.