The first thing you need to be secure online is safe software, and IMHO it is the only thing you need to do. If you don’t go to the dark side of the web, you can be pretty sure about your security with latest software. But I was puzzled seeing this . Some people are still using versions of browsers, that I only have heard about. Nope, it is not good old Netscape Navigator (I’ve used it 🙂 ). Any version of Internet Explorer below 7 will open your system to the world like troy was with Trojan horse.
So Paypal is going to stop allowing access for people who use unsafe browsers. They say some folks are using not only Explorer but version 4 & even 10 year old version 3! 
Some folks are still using Internet Explorer v.4, and v.3, which is about 10 years old 😐 I assume theese are very old machines and its users are not concerned with anything that is happenig in the world of network-security.