Systems and methods for providing image-based security measures

1. A computer-implemented method comprising:

initiating, by a computing system, a challenge response process to determine whether a user is legitimate, wherein the challenge response process comprises an image category associated with a recognized category label and wherein the recognized category label describes a subject depicted by the image category;

displaying, by the computing system, during the challenge response process, at least one image associated with the image category;

receiving, by the computing system, a user input, during the challenge response process, indicating whether the at least one image is associated with the recognized category label; and

determining, by the computing process, whether the user is legitimate based at least in part on a successful completion of the challenge response process.

2. The computer-implemented method of claim 1 , further comprising:

determining that the user input indicates that the at least one image is associated with the recognized category label; and

providing an indication that at least a portion of the challenge response process is successfully completed.

3. The computer-implemented method of claim 2 , wherein the recognized category label is presented during the challenge response process via at least one of 1) a natural language description or 2) a multiple choice selection.

4. The computer-implemented method of claim 2 , wherein the at least one image is included in a collection of images displayed during the challenged response process, and wherein the user input is included in a collection of user inputs received during the challenge response process.

5. The computer-implemented method of claim 4 , wherein each user input in the collection of user inputs corresponds respectively to each image in the collection of images, and wherein the indication that at least the portion of the challenge response process is successfully completed is provided when at least a threshold quantity of user inputs in the collection of user inputs correctly indicate one or more respective recognized category labels for corresponding images in the collection of images.

6. The computer-implemented method of claim 1 , further comprising:

displaying, during the challenge response process, at least one second image that is below a specified confidence threshold level of being associated with the image category;

receiving a second user input during the challenge response process, the second user input being received subsequent to the at least one second image being displayed;

determining that the second user input indicates that the at least one second image is unassociated with the recognized category label; and

providing an indication that at least a portion of the challenge response process is successfully completed.

7. The computer-implemented method of claim 1 , wherein the challenge response process is initiated in response to determining that a content item to be posted via a social networking system is associated with an illegitimacy confidence score at least meeting a specified illegitimacy score threshold.

8. The computer-implemented method of claim 1 , wherein the at least one image is determined, based on an image classification process, to be associated with the recognized category label, and wherein the image classification process utilizes at least one image classifier trained based on a set of images associated with the image category.

9. The computer-implemented method of claim 8 , wherein the set of images is updated via the social networking system over time.

10. The computer-implemented method of claim 1 , wherein the at least one image is at least one of 1) selected to exclude a representation of a face, 2) modified to remove the representation of the face, or 3) modified to obscure the representation of the face.

11. A system comprising:

at least one processor; and

a memory storing instructions that, when executed by the at least one processor, cause the system to perform:

initiating a challenge response process to determine whether a user is legitimate, wherein the challenge response process comprises an image category associated with a recognized category label and wherein the recognized category label describes a subject depicted by the image category;

displaying, during the challenge response process, at least one image associated with the image category;

receiving a user input during the challenge response process indicating whether the at least one image is associated with the recognized category label; and

determining whether the user is legitimate based at least in part on a successful completion of the challenge response process.

12. The system of claim 11 , wherein the instructions cause the system to further perform:

determining that the user input indicates that the at least one image is associated with the recognized category label; and

providing an indication that at least a portion of the challenge response process is successfully completed.

13. The system of claim 12 , wherein the at least one image is included in a collection of images displayed during the challenged response process, and wherein the user input is included in a collection of user inputs received during the challenge response process.

14. The system of claim 11 , wherein the instructions cause the system to further perform:

displaying, during the challenge response process, at least one second image that is below a specified confidence threshold level of being associated with the image category;

receiving a second user input during the challenge response process, the second user input being received subsequent to the at least one second image being displayed;

determining that the second user input indicates that the at least one second image is unassociated with the recognized category label; and

providing an indication that at least a portion of the challenge response process is successfully completed.

15. The system of claim 11 , wherein the at least one image is determined, based on an image classification process, to be associated with the recognized category label, and wherein the image classification process utilizes at least one image classifier trained based on a set of images associated with the image category.

16. A non-transitory computer-readable storage medium including instructions that, when executed by at least one processor of a computing system, cause the computing system to perform:

initiating a challenge response process to determine whether a user is legitimate, wherein the challenge response process comprises an image category associated with a recognized category label and wherein the recognized category label describes a subject depicted by the image category;

displaying, during the challenge response process, at least one image associated with the image category;

receiving a user input during the challenge response process indicating whether the at least one image is associated with the recognized category label; and

determining whether the user is legitimate based at least in part on a successful completion of the challenge response process.

17. The non-transitory computer-readable storage medium of claim 16 , wherein the instructions cause the system to further perform:

determining that the user input indicates that the at least one image is associated with the recognized category label; and

providing an indication that at least a portion of the challenge response process is successfully completed.

18. The non-transitory computer-readable storage medium of claim 17 , wherein the at least one image is included in a collection of images displayed during the challenged response process, and wherein the user input is included in a collection of user inputs received during the challenge response process.

19. The non-transitory computer-readable storage medium of claim 16 , wherein the instructions cause the system to further perform:

displaying, during the challenge response process, at least one second image that is below a specified confidence threshold level of being associated with the image category;

receiving a second user input during the challenge response process, the second user input being received subsequent to the at least one second image being displayed;

determining that the second user input indicates that the at least one second image is unassociated with the recognized category label; and

providing an indication that at least a portion of the challenge response process is successfully completed.

20. The non-transitory computer-readable storage medium of claim 16 , wherein the at least one image is determined, based on an image classification process, to be associated with the recognized category label, and wherein the image classification process utilizes at least one image classifier trained based on a set of images associated with the image category.