The terms "Sign up" and "Sign in" are not something unfamiliar to anyone who uses the Internet.If you need to be a member of any website,you gotta SIGN UP.It means you got to fill up an application which asks you for some details which depends on the website.They ask you the "name" ,"date of birth" and many more.but why this SECURITY IMAGE??
I know you have seen this hundreds of times,but you never cared.It's like,okay you asked me to do this and I did it.Some of you might already know the story behind this.This post goes to the excluded set.
If this security image was not on facebook sign up page, I bet you the facebook server would be crashed within few days or let's say a week.This is not applicable only to facebook;any webpage on earth. This image is used on purpose of identifying whether you are a human or not.Let me explain it this way.
You can write a program(call it a spam) which can automatically generate new users for a certain web page(If you are good in hacking).It can use a fake name randomly with random fake details.So what happens if it continuously introduces new users?"There is a limit for anything" right?So definitely the server would crash.
The solution is introducing a security image(PHP captcha),and that is where the hacker fails;in identifying the letters in the image.Which we believe the identification could be done only by a human.That gives the solution.That is why all the web pages are included with this security image confirmation.Hope you learned something from this post.
"Someday someone is going to hack the security image too" wait and watch.