Copy this into the ALT tag of any image:

This is a test to see how ckeditor handles alt tags with curly quotes & other characters. What's going to happen? What’s going to happen with this curly apostrophe.

This is what CKeditor does (note unaltered curly quotes):

<img alt="This is a test to see how ckeditor handles alt tags with curly quotes &amp; other characters. What's going to happen? What’s going to happen with this curly apostrophe." src="/images/test.jpg" style="width: 50px; height: 50px; " />