用户代理可以被伪造.验证码已被破解.有效的cookie可以与页面请求一起发送回您的服务器.合法程序(例如Adobe Acrobat Pro)可以在一个会话中进入并下载您的网站.用户可以禁用JavaScript.由于没有标准的措施来衡量正常"的用户行为，因此无法与机器人区分开来.

User agents can be faked. Captchas have been cracked. Valid cookies can be sent back to your server with page requests. Legitimate programs, such as Adobe Acrobat Pro can go in and download your web site in one session. Users can disable JavaScript. Since there is no standard measure of "normal" user behaviour, it cannot be differentiated from a bot.

换句话说:要做的只是将用户吸引到某种形式的交互式聊天中，并希望他们通过图灵测试，那么他们又可能是一个非常好的机器人.

In other words: it can't be done short of pulling the user into some form of interactive chat and hope they pass the Turing Test, then again, they could be a really good bot too.