[0x0]

When the author claims self-signed applets run in a sandbox, I believe that's incorrect. Even the warning shows the sandbox becomes disabled.

[jtheory]

Yeah, that's wrong.

UNsigned applets by default run in the sandbox; signed applets (including self-signed) run with full permissions unless you specify otherwise in the HTML and in the JAR manifest (where you can explicitly request sandbox-only execution).