I got the following reply in a different thread:
There really is no link between your gmail account and the bitshares account .. AFAIK entering a valid mail address is only required as an entropy source for the random passphrase
There is NO association between your bitshares account and your gmail account ..
also note that NO ONE will ever be able to send you your passphrase as it is only stored in your brain .. no where else ..
so please take the backup advises serious
No that I have read what you exactly did, let me rephrase .. the mail address you entered in the faucet is used to prevent spamming of accounts on the blockchain .. the faucet will only pay for one account per mail address ... once you have your own funds you can register as many as you like .. but the faucet helps to get over the initial-registration-with-no-funds chicken-and-egg problem ..
hence the restriction to one account per mail at the faucet ...
AFAIK, there has been a discussion whether to maybe use the mails from the faucet to send out security announcements of some kind .. but IIRC the consensus was to not use them for marketing and for sure not gonna sell them at all cost