Oh...
1 -
http://www.q2c.cc/crawler/calculator this chart not relevant. multiply the value by 2 with new miner
2 - pool shows no accurate statistics
3 - Botnet... this is a familiar concept (and nothing can be done
Thank you krecu for your answer. I didn't know that the chart was not up to date. To avoid botnets, can't we use captcha when creating a worker ?