Proxy Detector
The Proxy Detector plugin is used to detect the proxy settings of the respondent and also records the respondent information that is captured through Moffitt’s Maxmind subscription.
This plugin is used to allow or restrict to fill out the survey or form to those respondents who use proxy-server for web-access.
To apply this plugin specify following parameters:
Access* - Select whether to allow or prohibit an access if the proxy detection service is not available.
Proxy Threshold* - Likelihood of fraud threshold at which the respondent should be rejected. The lower the value is, the more respondents will be rejected, but the less is the probability of letting someone who is using a proxy into the form/survey. Default setting is 15%.
Allow to proceed* - Select the “Yes” option if you want to allow the respondent to enter the survey even if they are using a proxy detector or “No” option if you want to prevent the respondent from entering the survey if they are using a proxy detector and automatically redirect them out. In both cases, plugin will log the data.
http://Form.com uses MaxMind third party to check proxy setting of a form/survey respondents.