I don't think it helps to turn this into a "political discussion" rather than look at what might be happening. And it could be lack of Java 1.6 on Mac (Vista has 1.6.3) or coding and display or WebKit.
And yes, it is now a popular target for trojan horses and malware and attempts to find vulnerabilities in anything like a "social" web site, or SQL (which saw 10s of thousands of servers compromised over the weekend but now cleaned up). Which would impact a lot of network traffic and congestion, and maybe not limited to just the two mentioned.
I tend to run with javascript disabled, along with plug-ins, except for specific sites.
If you have enabled Safari's developer menu or debug, there should be option to change the user agent. Both platforms. "Inspector" can display what a web page is doing and point out code and bugs or performance issues with loading an element, memory use, threads.
If you do use Firefox, be sure to use NoScript to help block XSS, redirects, and other alerts.