Cons of Blogging?

I read an online article today about blogging:

http://news.yahoo.com/s/nm/20050826/us_nm/bizfeature_blogging_dc
(link now expired)

There are some tidbits from the article that are worth considering. According the article, many companies are beginning to write company manuals to regulate and advise employees on the use of blogs. One company, Sun Microsystems, cautions blogger's to

"...protect corporate secrets and...."using your Web log to trash or embarrass the company, our customers, or your co-workers, is not only dangerous but stupid."

Likewise, the article mentions Mara Levin, an employment attorney who notes:

"Some companies also "are looking to see if an employee has a blog before they hire them. You learn a lot about a person by reading their blog."

In a word - Don't write anything on a blog that you don't want others to know about. Sounds, like a rather obvious thing to write, yes? But think about the ubiquity of the web in modern industrialized countries like the U.S. Your average 13-year old in the U.S. can start a blog, if not at home, then at a friends house, or at the local library. Think of some of the foolish things that you have said, thought or wrote when you were younger. Hmmm...think of some of the foolish things you wrote or said last week!! Do you want them immortalized in blog? Various organizations (such as: http://www.archive.org/ ) have been archiving the internet, taking "snapshots" of web-pages and storing them indefinitely in archives. Is what you are blogging now something that you want the world to know about in 5 years? 10 years? 20 years?