Infecting malware, exploiting holes in the browser, storing data via local/session/appCache, tracking me (google analytics), loading flash, displaying ads, redi

Infecting malware, exploiting holes in the browser, storing data via local/session/appCache, tracking me (google analytics), loading flash, displaying ads, redirecting me to see an ad before the content... The list goes on and on, sure you can do most of these without javascript, but by that point I've moved on and blacklisted your site. Is it better to be overly secure, or underly secure?