Now this is insane! The internet that we use every day actually has weight to it.

Some scientist actually did the math and was able to figure out that all the "internet" together actually had mass, he said that it weighed a total of two ounces, and one email weighs about Two Ten Thousanths Of A Quadrillionth Of An Ounce'

http://www.npr.org/blogs/krulwich/2011/12/21/144066248/lets-weigh-the-internet-or-maybe-lets-not