Looking at some of the site statistics at The VG Press, it shows 82% of users reporting Java support enabled. One must then ask, WHY? Why do you have Java enabled? Java is a cross-platform language that in terms of what it provides as a browser is Java applet support.
Here are some examples of Java applets from Sun’s website:
If you can see those, you ought to go and disable Java now. For the most part, Java has disappeared from the web. A few uses remain in some web-based games, and speedtests as an alternative to flash, but that’s pretty much it. There is no reason to have it enabled by default.
I frequent ChessGames.com which uses an applet to allow to view games, so I have it selectively enabled for that singular site. This is what I would suggest to do with Java, if you need it at all in your web browser.
If you just need to disable Java entirely, that’s an options in your preferences (Edit->Preferences) under the Content tab.
To do this in Opera you’ll need to go to your preferences (Toos->Preferences) then under the advanced tab go down to Content. Disable Java system wide is an option there, which you’ll want to do. Then click Manage Site Preferences in order to selectively enable it.
To do this in Internet Explorer, I only have the option to globally disable Java, and no way to selectively enable it, as it’s not an option for Trusted Zones. For disabling Java, you’ll go to Internet Options (Tools->Internet Options), then under the Advanced tab scroll down until you see “Use JRE 1.X.X for applet” and uncheck it.
Java has had a long history of security issues, and even that notwithstanding, the more plugins you have running, the more possibility there is for something to go wrong, as well as the more that has to be loaded. For the majority of cases, I’d suspect Java goes completely unused, so letting any old site make it available is wasteful and potentially harmful.