members could cross-post entries from their diaries related to specific topics. The most popular circles include "Depression", "Relationships", "Poetry", "Love & Passion", and "Advice Wanted". Two diarists posted entries while on assignment at McMurdo Station, Antarctica during 2001 – possibly making Open Diary the first online community to have people writing from all seven continents. Open Diary introduced the premium service Open Diary Plus in 2001, a paid version of the original Open Diary. In addition to freedom from advertisements, Open Diary Plus offered several new features, including the ability to block specific users from reading the diary and the ability to organize the diary into chapters. The free and paid versions of the site were temporarily separated into FreeOpenDiary.com and OpenDiaryPlus.com. The two sites were later recombined, with free and paid memberships both remaining available at OpenDiary.com. A major upgrade to the Open Diary software was released in September 2003, adding the "Favorites Only" (later Friends Only) option for diary access, private notes, member interests, and other features. At the end of 2003, there were over 218,000 diaries active on the site. During 2004, privacy options on the site were further expanded, allowing users to set individual entries as "Favorites Only" and selecting who could read Favorites Only entries on a person-by-person basis. On September 11, 2004, the site was subjected to a major hacking attack, during which the site's databases were accessed and several weeks of diary entries were erased. In April 2005, a new diary interface was added, giving users the option of including profile pictures and lists of their interests and favorites in their diary pages. A Lifetime Membership level of paid subscription was added in February, 2006, granting Open Diary Plus privileges for the life of the site for a price of $100 USD (raised to $150 in 2009). A need for additional revenues to cover server and security costs resulting from the 2004 hacking attack was cited as the reason for adding this option. Teen Open Diary and Quit Smoking Diary were discontinued in May 2006, and members were given the option of transferring their diary to the main Open Diary site. Also in 2006, the OD Boards were added to the site, a set of community forums that were moderated by volunteer Open Diary members. In February 2008, new administrative volunteers were added to the staff to help with technical support, rules monitoring,