Seems good to me.
Crime must be stop and for that some measure should be taken which not very convenient.
I think you shouldn't have any problem with this unless you are also doing something which is against law..
Anyone can gladly search through my all emails.
I don't have any problem with that.
By that logic, search warrants are useless except to those that are criminals. Therefore, we should do away with search warrants and due process, right? Would you like to share your email account and password with all of us since you have nothing to hide? Really think about what could go wrong if that were the norm.
My point is there needs to be a balance and it needs to lean heavily towards individuals right to privacy. I'm not a criminal, but I also don't blindly trust other people, companies, or the government to use my personal information responsibly at all times (now or in the future). There are all kinds of ways that someone could make your life miserable by misusing or being careless with your data. For this reason, I don't use Gmail. It's not because I'm a criminal. It's because I just don't like the way they use your data for aggressive (intrusive in my opinion) levels of advertising. Basically, I don't have any confidence that Google respects user's data or their right to privacy.
Having said that, I certainly don't feel sorry for this guy for a few reasons...
1) He is a pedophile. Enough said.
2) He is super stupid. Who would be dumb enough to send child porn images through any email and especially gmail which tells you upfront that it is scanning all your data.
3) What he was doing is VERY illegal, immoral, and harmful to others. Google cannot allow their services to be used for such blatant illegal activity any more than a bank can knowingly launder money for the mob. They have every right to protect themselves from this level of misuse. Even if they weren't scanning emails/images for advertising purposes, I feel that this level of automated scanning for highly illegal activity is justifiable.