Manga Tutorials is an art community which is all about sharing one’s artwork with other members. Discussion about password protection has come up in the forum and I agree that password protection in albums is counterproductive to building a community therefore password protection in albums has been taken down for Regular Members.
If you would like to password protect your albums, you will have to acquire Premium Membership. To upgrade your account, log in, go to Dashboard and within the Dashboard block, look for Upgrades (above your avatar). Rates range from $4.95USD for one month to $29.95USD for a year (or $2.50/month).