Try interactively the following or reproducing what other Tclets here does, also try the error...
policy home
# this will produce an security check error:
socket foo.bar 2000
# this is ok from security standpoint (but will fail
# because nothing runs on that port):
socket {} 2000
# or
set homeHost [getattr originSocketHost]
socket $homeHost 2000
Or see the power (and dangers) of the Javascript policy:
policy javascript set s [browser::openStream _blank] browser::writeToStream $s "<h1>Hi !</h1>" # and now really fun: let's clone ourselves: browser::writeToStream $s "<embed src=[getattr originURL] height=400 width=400><br>" # Don't forget this one: browser::closeStream $s
click in and start typing Tcl commands (ps: no you can't
paste!):