Suppose that I�m implementing a web site, based on Ci, for electing the most popular person. Everybody likes Diane but Peter hates her. Can peter alone influence the system enough to remove Diane for the first place?
Let me quote a part from Chapter 2 (Section 2.3.6) that will help answer your first question.
In a site where anyone can contribute content, is there anything that stops your competitors from giving you an unjustified low rating? Good reviewers, especially those that are featured towards the top, try to build a good reputation. Typically, an application has links to the profile of the reviewer along with other reviews that they have written. Other users can also write comments about a review. Further, just like voting for articles at Digg, other users can endorse a reviewer or vote on his reviews. As shown in Figure 2.17 taken from epinions.com, users can �Trust� or �Block� reviewers to vote whether a reviewer can be trusted or not.
The feedback from other users about how helpful the review was helps to weed out biased and not helpful reviews. Sites also allow users to report reviewers who don�t follow their guidelines, in essence allowing the community to police itself.
Regarding your question on the concepts being applicable to other languages, the answer is yes!
These concepts are applicable to content in other languages. I leverage Lucene for text processing and it has a rich set of analyzers for non-english related content.