Just one example of a pro-social use case. If we all have bots then we can simply tell our bots to filter information and automate shopping. This would exclude a lot of the attacks (not all). The reputation economy would mean every bot which is anti-social or evil or harmful gets down voted, a bad score, etc.
Sybil attacks and botnets will still exist but the idea is that the most effective and popular bots will be the bots which people appreciate (in theory). Also in theory you can set up the bots so that for instance Alice's bots have the reputation of Alice as a verified bot and if the bot does anything bad it damages Alice's reputation. Unverified bots or bots with no reputation would be the ones to be concerned about.
Pseudo anonymity would mean I do not need to know who is behind the bot. I just need to know via cryptography that someone with a good reputation in the community is behind it. When everyone has their bots then the good and useful bots gain the advantage. When it remains a mysterious technical thing, well then I still may have access to these bots due to my technical abilities but the problem is the people who will need them the most will have to in essence pay the bots run by technical people (just like bots on Steem now).
I see no stopping markets from forming, and bots from proliferating. I think the benefits far outweigh the risks if the wisdom aspects I mention can be implemented. It might be true that bad actors can get enhanced wisdom from it but it means you and I also will get these enhancements. I don't think the bad actors will have as much of an advantage until of course they do what they always do and find new attacks. Unavoidable.
It is technically impossible to create a new technology which can vastly improve the condition of the world without any risk of it being turned against us. The Internet, social media, even the printing press, can be turned into a weapon. In fact, all of them have been weaponized in some fashion, but I'd rather have it too so I can have a level playing field.