The Google reCAPTCHA function is not supported with EZproxy. The reCAPTCHA functionality on sites is based on embedded Google security verification that is incompatible with EZproxy. When a resource provider uses reCAPTCHA, they register their domain with Google. EZproxy works only when it is able to replace the domain of a resource provider, which conflicts with reCAPTCHA’s verification.
Resource providers have previously advised to use Host or Domain lines that include “google.com.” It is strongly discouraged and will likely result in problems with other resources in your EZproxy configuration. The problem is that if other resource providers have embedded Google functionality on their website which requires proxying. This can cause problems with other stanzas due to the vast presence of Google on the web.
For some resource providers we have found that they can disable reCAPTCHA on their site for EZproxy users, this is the most viable option.