No-JavaScript notes

I was asked about the demographics of no-JS users, and didn't have a great or solid answer ("Corporate intranet users? old-browser users? users avoiding banner ads?"), so I went looking. Here's what I found:


 * Reasons for disabling JavaScript
 * Security
 * For security - (javascript vulnerabilities in browsers)
 * Corporate proxy disabled it - (for intranet security)
 * For privacy - (preventing some tracking/advertising systems, usually coupled with disabled-Cookies)
 * Preference
 * For annoyance prevention - (to prevent things like animations, particularly for users who find these overwhelmingly distracting)
 * Performance
 * For faster site downloading - (less to download (bytes))
 * For faster browser rendering - (less to calculate (complexity))


 * Other reasons for which users encounter the no-JS version
 * lost connection mid-download - (especially mobile users, and unstable wifi users)


 * Methods for disabling JavaScript
 * NoScript and similar browser extensions
 * Browser settings
 * Connection proxy
 * A browser that doesn't support it - (lynx, etc)


 * Prevalence
 * 2010 - 1.6% average (2.06% in U.S., 0.26% in Brazil) (according to developer.yahoo.com)
 * 2013 - 1.1% in U.K. (according to gds.blog.gov.uk
 * 2014 - ???
 * (newer stats, and other Reliablesources, would be appreciated. Statcounter doesn't yet reveal no-JS usage)


 * Sources and good links
 * http://www.punkchip.com/2011/03/why-support-javascript-disabled/
 * https://stackoverflow.com/questions/337570/is-it-worth-it-to-code-different-functionality-for-users-with-javascript-disable
 * https://stackoverflow.com/questions/9478737/browser-statistics-on-javascript-disabled
 * http://webaim.org/projects/screenreadersurvey5/#javascript
 * https://gds.blog.gov.uk/2013/10/21/how-many-people-are-missing-out-on-javascript-enhancement/
 * http://halls-of-valhalla.org/beta/articles/javascript-disabled-should-i-care,49/
 * Progressive enhancement
 * Unobtrusive JavaScript