- Provide mandatory questions on sign-up, some requiring typing actual text. Example: What is your favorite data mining software?
- Do not allow new members to use your social network e-mail functionality right away. Grant email access after 48 or 72 hours.
- Do not allow members to reach more than 20 other members per day, via email.
- Captcha on sign-up form.
- Have new members confirm their email address.
- Let members refuse to receive email from others members, if they wish.
- Do not allow posting on a member's wall (member profile page).
- Individually approve or reject all applications for membership, based on email address, country and answers provided to sign-up questions.
- Suspicious sign-ups: do a search on the applicant's name, email address, and his submitted bio before approving membership.
Download my PowerPoint presentation on this subject.