Is Lout a virus spreader?

[Jeff Kingston]

I think I can see a way to turn Lout into a virus spreader.

Write a shell script that uses existing system commands to read a
user's mail alias file and send a particular mail item to everyone
in the file, a message something like this:

    Subject: real cool document I just found

    Hi! here's a real cool document I just found, like to have a
    look at it?  Just run Lout over it!
    ============================================================
    def { ... }
    @SysInclude { doc }
    @Doc @Text @Begin
    ....
    @End @Text

The definition contains a @Filter which contains this shell script,
and the document body executes it.  You could bury the nasty definition
a couple of pages down in the document where the casual observer would
not notice it.  I guess this is what Ian had in mind.  He says:

    [The @Filter] feature should only be available if you
    invoke Lout in an `unsafe' mode, and the default should
    be to invoke it in a safe mode.

    Otherwise there is no safe way to format documents
    supplied by other people.

Any comments?  Ideas for even nastier things?  Suggestions for what
should be done about this, if anything?  It would be easy to add a
command line flag to disable the @Filter feature.  Is that the answer?

Jeff.