Some messenger protocols being blocked?

[Chris Jones]

I am having issues connecting to the MSN protocol using GAIM. I have
been trying for several weeks now to no avail. A reliable source told me
that Microsoft have begun blocking users who try and use the MSN
protocol with a third-party client. i.e. GAIM. Is this true? And if so,
how long would it be before other companies do the same thing such as
ICQ and Yahoo?

Chris Jones