The venom expressed in many of the posts on this subject has puzzled me since I first started to follow this subject. What had I missed? BOTs have been around for years. If you are a patient trader with deep pockets, they tend to provide more opportunities than they take away.
Most of the complaints seem to be coming from the day traders. These are the traders who take direction from charts and try to protect themselves with tight stop loss orders. They often look to turn a profit on the bid-offer spread. Their collective behaviour is predictable and that makes them vulnerable.
BOTs are simply bigger fish who feed off the minnows. It is probably the natural order of things. Banning BOTs is a bit like trying to make sharks illegal.