Why are singletons considered to be a bad practice?
<h3>Duplicate:</h3>

<blockquote>
  <p><a href="http://stackoverflow.com/questions/137975/what-is-so-bad-about-singletons">What is so bad about Singletons?</a></p>
</blockquote>

<p>I was reading <a href="http://stackoverflow.com/questions/678669/concurrency-asp-net-best-practises-worst-practises">this</a> question, and was surprised to see that (s)he considered a singleton to be considered a "bad practice," and in fact thought that this was common knowledge.</p>

<p>I've used singletons quite a bit in any project that uses iBatis to load the queries from XML.  It great improves speed in these instances.  I'm not sure why you wouldn't use them in a case like this.</p>

<p>So... why are they bad?</p>
