I like to consider myself fair and balanced when speaking about most topics. To educate the uneducated and to balance things out a bit I have compiled a list of 5 problems we will likely run into when we reach the Semantic Web. Each problem is a side-effect of advances in technology, rushes to fill new niches, or the previous two plus the desire to make a quick dollar.
1. Reduced anonymity on the Web
Unless you're already taking active measures to keep yourself non-indexed you may find that in the Semantic Web information about your identity, interests, and habits are trivial to discover. When you sign up for an account on sites like MySpace, Digg, Slashdot, etc you are feeding them information about yourself during and after registration — with your activities and contributions.
As the amount of available personal information increases we could begin seeing Websites that rely on querying the "Web as a database" for information about its visitors for mission critical functionality. If (once?) this change takes place having personal information on the Web may become the comfortable norm. One day we may see a shift in the importance of anonymity. Openness and transparency may become the "in thing."
2. Increased invasion of privacy
This problem stems from the issue of reduced anonymity on the Semantic Web. A Web that exposes vast amounts of information about everyone has its drawbacks. One downside to having so much information easily accessible to anyone is there will always be someone ready to abuse that information to make a quick dollar.
We may find ourselves in a new era of unwanted personalization. Contextual ads that examine a Website's content for hints of interests may be replaced with ads that target specific visitors based on their personal preferences, behaviors, lifestyle, friends, income, etc. In a similar way we will likely notice that e-commerce Websites will become better at figuring out just what it is we are going to want next.
Invasion of privacy brought about by the abuse of personal information — which would be more accessible than ever — will prove itself quite annoying. But we already have privacy issues now, don't we? If you've ever gotten a spam email then you know the answer is "yes, " and there is so much more room for the problem to get worse before things will get better.