In a way I agree with you. Moore's law has affected the Drake equation in ways we don't even know yet. I personally think the Fermi Paradox is pure BS and not well though out, however, the Drake equation seems to have stood up to scrutiny.
SETI (at least the current trend) is searching for extremely narrowband carrier signals that Doppler shift due to planetary rotation. The Doppler shift is extremely important since if it is not there, we know the signal is either terrestrial or an artifact of the equipment itself. The other thing that is very important is the two-antenna approach. If two antennas, separated by a thousand miles, were pointed at the same patch of sky, this would not allow a satellite to "spoof" the system. First, the likelihood of it being within the footprint of both antennas are exceedingly small, and the Doppler characteristics between the two antennas would rule it out if such a thing happened.
All that said, I agree with the advances in communications technology can cause a search to be futile for many types of broadcasts. Frequency hopping spread spectrum and the like will make it far harder to detect a tool building species that uses radio (EM).
To be fair to the other side there is another factor in this conjecture. A race is progressing along and figures out that the electromagnetic spectrum is the only real practical method of long-range communications. So high-powered transmitters are built as this technology is in its infancy. As the engineering and science of radio advances, they figure out that tight beam, spread spectrum, synthetic aperture, frequency hopping, etc. are a way of not only saving power, but also bandwidth. So for the first 50 years they have been "bleeding" EM into space across a huge range of frequencies into and ever-increasing sphere of radio noise. However, do to technological advances, this RF that is being bled into space quiets down dramatically.
Now, lets jump a few years. This race has expanded off its initial planet and is exploring the solar system it resides in. (IMHO, star travel still remains firmly in the realm of SiFi) Somehow they have to communicate. So again high power transmitters are employed to accomplish this. Light is not out of the question, however, microwave is easy, cheap, less pointing accuracy requirements, and wont be drowned out by the star. So suddenly this race again is radiating RF into the universe. So according to this scenario, a race can emit RF then grow silent for a time, and then restart emitting RF.
I also agree the movie "Contact" is pretty shallow in many ways. Headphones? Not a chance. Most SETI searches are done with computers looking at millions of frequencies simultaneously. Also, SETI is not looking for, nor is it expecting any modulation. That would long ago have been lost in the Interstellar Medium (ISM). All that can reasonably be expected to be detected a faint signal from the narrowband carrier itself. In fact due to the signal-to-noise (S/N) characteristics, the narrower the band that is being searched, the better. Some searches are looking for signals that are no wider than .8 Hertz.
Just my two cents.
YOU'RE too modest, RA.
Your comment is worth at least $0.05.
just a topic bump
Refuting Fermi: No Evidence for Extraterrestrial Life?
John B. Alexander
National Institute for Discovery Science
http://www.nidsci.org/pdf/fermi.pdf
related FR topics:
Cosmic Conundrum [Brief essay on multiple universes and the Anthropic Principle]
Time ^ | Monday, November 22, 2004 | Michael D. Lemonick; J. Madeleine Nash
Posted on 11/26/2004 1:33:59 AM PST by snarks_when_bored
http://www.freerepublic.com/focus/f-chat/1288684/posts
The Fermi Paradox - Are We Alone in the Universe
Posted on 05/19/2004 12:46:40 PM PDT by Conservomax
http://www.freerepublic.com/focus/f-news/1138670/posts