Recently I have been testing a patch for the captcha module and a custom module to ban temporarly the spambots that usually attack my Drupal 7 website. The results could be promising. Here is my provisional solution.
In my opinion a big problem for the 2.0 websites are the spambots, annoying programs designed to invade your web forms with a lot of spam. After multiple attempts, I have found a nice compromised that it helps me to reduce this phenomenon, saving my bandwidth. Below I explain the Drupal 7 modules which I installed and some settings. At present I haven't totally erased these attacks but I am studying a new approach to block them (in a next article if I'll solve some essays).