You had to manually enter 2 layers of captcha, to register for a token, then wait 1 hours to redeem.  The token was generated 1 per IP per hour.  

The site had over 55k hits in 2 days 22k+ unique.  The registration process was secure enough and since it took only 2 days to reach max address... I doubt anyone had time to invest in making a bot.

Just so you know... this is over now we are almost finished distributing all the coins