For all the hype about Wikipedia, about how thousands of people work together to improve the site and the collective knowledge it offers, the reality can be a lot different.
1. It may represent the collective wisdom of crowds, but the crowds have a problem with grammatical errors, misspellings and poorly organized entries. The site should enlist copyeditors to catch these problems. I've seen a number of entries that contained redundant information because an editor didn't review the entire piece.
2. The site tries to be neutral and objective, but Wikipedia is much more subjective and less authoritative, than it claims to be. Different contributors' personal interests often skew the emphasis of the information. One entry emphasized a minor career move while overlooking major accomplishments.
3. Despite the concept that every contributor to Wikipedia serves as a fact checker, I've seen factual errors in articles. For example, an introduction claimed the subject to be an only child when the body of the article included information about the subject's sister. Yes, I corrected the information but the article was more than 18 months' old, and should have been corrected a long time ago.
4. It may be easy to post information, but it's not so easy to keep your article on the site. Wikipedia has self-proclaimed watchdogs whose main goal is to delete entries -- sometimes minutes after the entries have been created -- even if they have no real expertise in the subject matter. One contributor's page says: "I like to specialise in clearing up Wikipedia of all the unnecessary articles, i.e. adverts and spam, which prevent Wikipedia from being enjoyed by those looking for serious information." The result: a self-selected group who should be called dis-contributors because they rarely add information and are too quick to delete entries made by others. While I understand the need to protect Wikipedia from frivolous entries, I think the dis-contributors could play an important role if they spent their time as fact checkers or copy-editors.
5. If you post information on Wikipedia, you must also commit yourself to monitoring your entries. Otherwise, the entries could be deleted or edited by others who may add irrelevant or incorrect information.