Accessibility review: page headings need to be marked up as such

On the "Connections" page, the "My connections - n" should be marked up as a heading.
On the "Search" page, the "Search by name or email" and "Search by interest" texts should be marked up as a heading.
On the "Privacy" page, the "Privacy settings" text should be marked up as a heading.
On the "Preferences" page, the "Preferences" text above the form should be marked up as a heading.

Suggest marking it up as a level 3 heading.

On the "Preferences" page, the "Email Notification" text and the "Twitter integration" text in the form should be marked up as a heading.

Suggest marking them up as a level 4 heading.