Is it possible to trigger an alert based on Text Matching of text in a web page's source? Normal text matching does not work since the text to match is non-rendered page markup (but visible in the page source)
You can build a powershell script around the invoke-webrequest command
For example this:
$test = Invoke-WebRequest 'http://gmail.com/'
$test.rawcontent
would probably display everything you are looking for.