11. A server for providing human verification using a contextually iconic visual public Turing test, the server comprising: a processor configured to: receive a request to verify whether a client is human controlled; select, by contextual criteria, a plurality of images each having one or more associated tags from a database; generate a challenge question and a corresponding answer set based on associated tags of a subset of the plurality of images, wherein the challenge question includes an animated tutorial with visual cues; present the plurality of images and the challenge question to the client; receive an answer to the challenge question or a rephrase indication from the client; if receiving the answer from the client, respond to the request by verifying whether the answer is contained in the answer set to determine whether the client is human controlled; if receiving the rephrase indication from the client, generate a rephrased challenge question having the corresponding answer set, wherein the rephrased challenge question includes the animated tutorial with the visual cues; and present the rephrased challenge question to the client; wherein the challenge question is more specific than the rephrased challenge question, and wherein the rephrased challenge question is more general than the challenge question.
11. A server for providing human verification using a contextually iconic visual public Turing test, the server comprising: a processor configured to: receive a request to verify whether a client is human controlled; select, by contextual criteria, a plurality of images each having one or more associated tags from a database; generate a challenge question and a corresponding answer set based on associated tags of a subset of the plurality of images, wherein the challenge question includes an animated tutorial with visual cues; present the plurality of images and the challenge question to the client; receive an answer to the challenge question or a rephrase indication from the client; if receiving the answer from the client, respond to the request by verifying whether the answer is contained in the answer set to determine whether the client is human controlled; if receiving the rephrase indication from the client, generate a rephrased challenge question having the corresponding answer set, wherein the rephrased challenge question includes the animated tutorial with the visual cues; and present the rephrased challenge question to the client; wherein the challenge question is more specific than the rephrased challenge question, and wherein the rephrased challenge question is more general than the challenge question. 15. The server of claim 11 , wherein the processor is configured: to receive a second answer to the rephrased challenge question from the client; and respond to the request by verifying whether the second answer is contained in the answer set to determine whether the client is human controlled.