Let Users Control Font Size
http://useit.com/alertbox/20020819.html

Nielsen, Jakob
Alertbox
2002

Abstract:

Sometimes technological progress backfires, and the 'better' technology turns out to be worse for users. The Web is no stranger to this problem, and has experienced many innovations that would have been best avoided. Examples include frames, changing the color of browser scrollbars, and scrolling text. Another example of harmful Web technology comes with the increasing use of style sheets, which let web designers specify the exact size of text down to the pixel. Unfortunately, many designers are using this ability, leading to reduced readability of an increasing number of websites.