9. A computer system configured to validate visual CAPTCHAs, the computer system comprising: one or more hardware processors programmed, via executable code instructions, to: generate a visual CAPTCHA including a plurality of visual patterns in a first configuration, wherein at least one of the visual patterns is configured to be manipulated by a human user to cause various amounts of overlapping of the visual patterns in order to produce different secondary images that are not visible in separate visual patterns of the plurality of visual patterns; provide to the human user an indication of a target visual pattern to be created in a produced secondary image of the visual CAPTCHA; receive input from the human user indicating a second overlapping configuration of the visual patterns that produces a moire pattern, wherein the moire pattern is configured to be perceived as including a first object by the human user viewing the moire pattern, and wherein an automated computer system analyzing the moire pattern cannot identify the first object; compare the second overlapping configuration to a predetermined target overlapping configuration associated with the target visual pattern; generate an indication of whether the second configuration was provided by a human based on said comparison; and transmit the generated indication.
9. A computer system configured to validate visual CAPTCHAs, the computer system comprising: one or more hardware processors programmed, via executable code instructions, to: generate a visual CAPTCHA including a plurality of visual patterns in a first configuration, wherein at least one of the visual patterns is configured to be manipulated by a human user to cause various amounts of overlapping of the visual patterns in order to produce different secondary images that are not visible in separate visual patterns of the plurality of visual patterns; provide to the human user an indication of a target visual pattern to be created in a produced secondary image of the visual CAPTCHA; receive input from the human user indicating a second overlapping configuration of the visual patterns that produces a moire pattern, wherein the moire pattern is configured to be perceived as including a first object by the human user viewing the moire pattern, and wherein an automated computer system analyzing the moire pattern cannot identify the first object; compare the second overlapping configuration to a predetermined target overlapping configuration associated with the target visual pattern; generate an indication of whether the second configuration was provided by a human based on said comparison; and transmit the generated indication. 16. The computer system of claim 9 , wherein the visual CAPTCHA is configured to update after an elapsed time, and wherein a prompt is provided to the human user to manipulate the at least one of the visual patterns after the elapsed time.