Mozilla have taken steps to block the Skype add-on from the Firefox browser for all users, and will actively block installs in the future.
You might think that Firefox has nothing to do with Skype, but there’s a sneaky Firefox add-on installed whenever you install or upgrade Skype. Originally it was an option during the Skype installation program, but for the latest releases you’ve probably not even noticed the “Options” page when you installed or upgraded Skype so it’s installed as default.
The Skype add-on automatically detects phone numbers in web pages, and re-renders them as clickable links. It’s quite cute, although it does sometimes incorrectly detect numbers and try to render them as phone numbers (even if they are eBay item numbers).
Mozilla say that the Skype add-on was responsible for 40,000 crashes of Firefox in just the last week and not only that but it can make Firefox run 300 times slower! Reading between the lines they’re fed up with users blaming Firefox for being unstable and running slow, so they’re prompting everyone with a pop-up to disable the Skype add-on with immediate effect.
In the mean time they say that they have recently established contact with the Skype Toolbar team, and will work with them to identify the issues that should be corrected, and will lift the soft block on future versions that address those issues.