If security is your biggest concern, NoScript is a good add-on. You can set it to allow or deny websites access to your computer as you see fit. The downside is that it is in no way convenient. You have to manually white list basically every website when you first try to access them. There can be half a dozen web address choices (or more) that come up and some of them could be necessary for functions of the website to work properly or they could be crap that you actually want to block. The domain names may be helpful in deciding which are which, but there isn't always a way of knowing which ones to white list or deny without some trial and error. I used NoScript for a good while, but finally got tired of messing with it whenever I visited a new website, so I removed it. It just wasn't worth the aggravation to me.