That is Stephen Hawking's recommendation--that we should not be looking for alien life out there because we might be telling them where we are. This has already gotten much play by IR types, as Drezner, among others, beat me to the punch again.
Drezner suggests that we need to gain some information for the purpose of early warning, but I think I have to side with Hawking on this: what would early warning do to help us? Hawking's basic premise is that any extraterrestrials that show up would have an extreme advantage so that we would be helpless (unless they are allergic to water, one of the stupidest premises in all of movies, thanks M. Night).* So, it is not clear what early warning would do, as either the governments of the world would cover up (like 2012) or the people would panic.
Sure, more knowledge is good, but the parallel of submarine warfare is apt. As subs hunt each other, they cannot use their active sonar to ping and find the adversary as it would reveal its own location. Passive sonar--listening with really good earphones--is the way to go, as you hear the noises the other guy makes but do not reveal your own location. So, the implications of Hawking would be to invest in passive technology (telescopes, other tools for measuring signals from space) but avoid blaring noise into space or sending distant probes.
This is a point that Star Trek has already demonstrated in the old TV show and then the first and worst movie--that probes can be boomerangs, but when they return, they come back with amped-up alien hybrids.
Drezner's best point is that some humans would be willing to betray humankind (as we see on V), so: "wouldn't Hawking's isolationist policy allow the quislings to monopolize the galactic message emanating from Earth?" As Mancur Olson taught us long ago, cooperation is quite difficult, and you will always have some folks who defect. Trying to keep all of humanity quiet would be impossible, particularly if it mean moving from broadcast to only cable provision of TV/radio.
The good news, as Drezner and others point out, is that if aliens want resources, there are plenty of places to find them. Columbus, the Spanish explorers and the rest were not seeking to kill the indigenous peoples with their germs, guns and steel. They just happened to be in the way for the search for resources and a shorter route to the Far East. Since space is much more three-dimensional (and eight if you ask Buckaroo Banzai), the aliens will probably not need to go through Earth or our solar system to get somewhere else. That is, unless Douglas Adams was right, that the Earth is in the way of a galactic by-pass.
And since there are many other planets, the odds of them wanting to mine our little planet for resources are low. Unless that is, there is something that we produce that is a scarce commodity across the universe. What could that be? Twinkies (no, that is probably just for folks in a post-Zombie America)? Skanky celebrities? Probably not as other alien civilizations will probably generate their own Paris Hiltons. What do we on Earth produce that would be desired by a technologically superior civilization?
I leave that to my readers to figure out.
* The remake of War of the Worlds was almost as stupid in its deus ex machina: that the aliens could not handle our germs. But they had a presence here from a long time ago plus why are we immune to their germs? How come their cooties are not as bad as ours? I guess if you ask Jared Diamond, he would say we have much more proximity to animals than the aliens who have been in space for generations.