When using wikis with K-12 students, a website with ads can be distracting and may sometimes link to inappropriate sites. Choosing a website without advertising would eliminate this concern.
Another issue related to advertising is spam. Wikis are open environments and marketers and vandals can flood a wiki with spam. Having a security protection program may help to alleviate this problem.
Matt Barton's blog on Embrace the Wiki Way! on May 21, 2004 discusses wikis and comments on their vulnerability. He makes a very valid point when he says,
'Wikis are protected not by code, or by law, but rather by the participation of an active wiki community. If you are proud of your entry, you will feel compelled to see what's up if you receive a notification that the entry has been changed and roll it back if it's obvious the page was vandalized or rendered less intelligent.'
An interesting issue was raised in 7 things you should know about Wikis. It discussed how a wiki represents the collective perspective of a group and that over time, the values, perspectives, and opinions of its users can become embedded in the wiki. It is felt that although a wiki is well suited to reflecting current thoughts, perhaps it is not effective in gaining an unbiased perspective on rapidly evolving topics. I am sure some of my colleagues will have formed a very informed opinion about this issue after completing this course.