Question

Enter certain text to verify you are human

I have observed this on numerous websites, including SO. I dont know a thing about hacking, but I don’t understand why is it required? Especially, in SO when making edits, sometimes it asks to enter some text to verify if it is Human or not.. I mean, how can a computer program (design for these kind of hacks) do edits (with SO’s rules and restrictions on editing) , and then save them?

Is there any other reason, these verification things are added on any website?

Answer 1

SO isn’t magic, it’s just receiving some HTTP posts, and responding to them. Indeed, it won’t even stop me from writing a script, though it will throw up the verification step if something indicates a nasty script (lots of posts per minute, lots of repetition). (Also, please don’t call nasty tricks “hacking”, it’s not polite).

Edit: How to repeat the above from a script, with bits that would make it look like I did it, editted out:

POST http://stackoverflow.com/questions/11989856/answer/submit HTTP/1.1
Host: stackoverflow.com
User-Agent: Mozilla/5.0 (Windows NT 6.0; rv:14.0) Gecko/20100101 Firefox/14.0.1
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-IE,en;q=0.8,en-gb;q=0.5,en-us;q=0.3
Accept-Encoding: gzip, deflate
Connection: keep-alive
Referer: http://stackoverflow.com/questions/11989856/human-verfication
Cookie: [THIS BIT EDITED OUT]
Content-Type: application/x-www-form-urlencoded
Content-Length: 471

post-text=SO+isn%27t+magic%2C+it%27s+just+receiving+some+HTTP+posts%2C+and+responding+to+them.+Indeed%2C+it+won%27t+even+stop+me+from+writing+a+script%2C+though+it+will+throw+up+the+verification+step+if+something+indicates+a+nasty+script+%28lots+of+posts+per+minute%2C+lots+of+repetition%29.+%28Also%2C+please+don%27t+call+nasty+tricks+%22hacking%22%2C+it%27s+not+polite%29.&fkey=[THIS BIT EDITED OUT]&author=&i1l=[THIS BIT EDITED OUT]

My browser sent that to the site. Send something like that, and you’ll have posted to this thread.