The dark side of Skype

Skype's free internet phone calls are a boon to millions. But it has a dark side which has largely gone undocumented: it hijacks websites.
Recently, I installed Skype on my computer at the request of my boss, in the belief it would improve communications between us. One of my duties is to administer our website, hence I frequently author pages for the site. But we have discovered that Skype sniffs around for phone numbers on a page, and when it finds them inserts a packet of code into the page to promote Skype. The end result on the page looks something like this:

It doesn't look like much, but the code is quite large, which can push up downloading times, for instance in email newsletters. At this stage, the only way I know to stop it hijacking the page is to exit Skype before authoring. There's an old (now very un-PC) expression which could apply in this case: Beware Greeks bearing gifts. (Refers to the Trojan wars, before you get upset.)