Well after we switched to one of the most popular forum platforms vBulletin you also get more people who try to hack and find loop holes.
Simular to why Windows has so many more viruses/malware created specifically for that OS when compared to the Mac.
So people are always hammering away trying to find way to do thing and we had individuals who where using scripts or bots or something to bog down our server with lots of repetitive searches
So we had to put reCAPTCHA in place as a road block.
So now we had to Replace "reCAPTCHA"
which is used by most Web-Site because Hackers have cracked the Code,
We have replaced "reCAPTCHA" with the New Questions road block.
Sorry its annoying at times.