For my high school, they did not block ports 6667 range, so I could java applet in high school.
For my college, that is also the same, however, for the university's wi-fi, they did block ports 6667. So I could not java applet on my laptop, only on their school computers.
But this was, of course, for networks where java users connect on different ports than mIRC users do. I can use the Efnet java applet just fine in school, since it doesn't use the port 6667 range, but in the 5,000s.
