squid and blank/empty passwords?

[scott at MIT.EDU (Scott Ehrlich)]

I am trying to establish blank passwords for some squid accounts, using 
htpasswd /etc/squid/squid_passwd name_of_user

When prompted for a password, I just hit enter twice.   The squid_passwd 
file still shows an encrypted password.   I've tried to delete it, leaving 
just the username and colon, but I cannot seem to get a blank password.

What is the magic?

Thanks.

Scott