This entry proves the point of the cited study
Lyman, Peter and Hal R. Varian, "How Much Information", 2003. Retrieved from http://www.sims.berkeley.edu/how-much-info-2003. Excerpts from the executive summary:

1. Print, film, magnetic, and optical storage media produced about 5 exabytes of new information in 2002. Ninety-two percent of the new information was stored on magnetic media, mostly in hard disks.

2. We estimate that the amount of new information stored on paper, film, magnetic, and optical media has about doubled in the last three years.

3. Information flows through electronic channels -- telephone, radio, TV, and the Internet -- contained almost 18 exabytes of new information in 2002, three and a half times more than is recorded in storage media. Ninety eight percent of this total is the information sent and received in telephone calls - including both voice and data on both fixed lines and wireless.

The following excerpts are from Chapter 8, Section III, Blogs (web logs):

Blogcount.com addresses the “blogosphere,” asking “What is its size, shape, color, true nature?” Blogcount collects and organizes the best reports and analyses on this subject. As of June 23, 2003, Phil Wolff estimates that there are 2.4 to 2.9 million active web logs. He bases his estimate upon statistics from centrally hosted weblogs....

He notes that this figure does not include smaller hosts such as Radio and Moveable Type or blogs hosted behind firewalls on private intranets.

If each blog is 50 KB, then the total size of the active blogosphere is 81 GB.