Does the republication and distribution of short excerpts from news articles with links to the original constitute copyright infringement or fair use?  The practice is common on the part of search engines, news aggregators and bloggers.  But is it permited?

Google has been involved in a lawsuit over the practice for some time.  Read more here.  More recently, Microsoft has agreed to comply with a cease and desist demand sent on behalf of Belgian newspaper publishers, as reported here.  Google's comment on its current dispute in Belgium appears here. SearchEngineWatch provides interesting commentary and background here.