This is where we break out the old Zawinski quote:<p><pre><code>  Some people, when confronted with a problem, think
 “I know, I&#x27;ll use regular expressions.”   
  Now they have two problems.
</code></pre>
I actually had to tell someone this who wanted to build a machine classifier. They wanted the classifier as a step in getting data for their research.  The problem was as far as I knew in the literature building the classifier would be a research project of its own.