Drupal.org recently did something similar with their issue tracker. Their rationale was that it's a performance issue, and there were large numbers of bots scra

Drupal.org recently did something similar with their issue tracker. Their rationale was that it's a performance issue, and there were large numbers of bots scraping the site using the advanced issue search. Requiring login for issue search allowed them to find out who was scrapping and then they could talk to them about what API improvements they needed, etc.