In the electronic world, noise is defined as unwanted disturbances superposed on a useful signal that tend to obscure its information content. Wikipedia:Electronics Genealogical noise is exactly the same thing; unwanted disturbances superimposed on useful information that tends to obscure the useful content. The more contact you have with the Internet, the more likely you are to see noise. The trick is being able to separate the noise from the useful information in an efficient way. Let me give some examples.
Facebook is a prime example of genealogical noise. The anecdotal evidence would lead you to believe that Facebook is a valuable genealogical resource. It well may be and my own personal experience would lead me to believe that it is, but it is a very noisy resource. It is very difficult to go on to Facebook without being distracted by the stream of messages from family and Facebook "friends." Hence, the amount of noise is excessive. It is also relatively difficult to separate out the valuable genealogical information from the unwanted or even misleading information. It is best considered a medium of communication rather than a source. Despite the noise, a Facebook account can be helpful in finding and making contact with relatives. To some extent, Facebook also serves the function of a forum for answering genealogical questions, but the high noise content severely limits its ability to function effectively. The main advantage of Facebook is its nearly universal reach.
How do you deal with noise on Facebook? Unfortunately it is a matter of self control. I say unfortunately, because the noise (distractions) seem valuable in themselves even though they have no genealogical content. One problem is that an overly expansive view of genealogy would include all inter-familial communications as part of your "genealogy." Personally, I avoid using Facebook to communicate with my children. I do that directly by email or telephone or video conference. The noise level on Facebook is just too high for me.
Reader is another source of genealogical noise. It seems like I add another blog or website regularly and tonight I came home to 93 posts. Almost my limit. Fortunately, Google Reader doesn't rise to the level of distraction of Facebook. Mainly, because I can pick and choose what is listed and skip anything that doesn't seem relevant. I do need to go through it periodically and weed out the excess blogs that have gone dormant or are no longer offering relevant information. That automatically cuts down on the noise.
Even Google, as a search engine, generates its own level of noise. There always seems to be something more to look at. Every once and while, I get distracted by the news of the world and get wrapped up in some story or another. I am not sure I would classify that as noise, unless you count the multitude of channels going on in my head all the time as noise.
Here's the deal, I think we all need to analyze what is and what is not noise in our surroundings. Maybe we have some habits, like reading the morning newspaper, that are really just noise. But I suggest that we all, (I am really writing about myself) need to filter out more of the noise and keep focused on the tasks at hand.