is picasa a safe way to share fotos

[iinfi]

i have not used google picasa much but i feel its a very insecure way to sharing fotos.
i find that all it gives us is a link to send across to people with whom we intend to share fotos.
but instead of the people concern if someone else gets the link, he/she can also view it. all in all it is not locked to any specific a/c.

suppose a@gmail.com wants to share fotos with b@gmail.com and c@gmail.com he will send them the link. by any chance if d@gmail.com gets the link he also can view it. it should be viewable by people logged in with b@gmail.com and c@gmail.com only.

is there such a feature in picasa?

[iinfi]

ok .. i found it myself ... posted this bit too early..