Except when they stand between your head and the road. I found mine pretty productive in the head suddenly meets road event. Mandatory helmet laws are counterproductive for cyclists. Helmets help more often than they don't
One of my friends had an interesting remark about the "privacy opt outs". It's that google always tracks you, no matter what checkbox you check or uncheck. Why not use the data they are already collecting about you to improve your daily life then.
Or you program the VCR and it starts and stops recording in time. But the TV schedule is so off that you miss that movie completely. I swear that in Croatia, in the 90's, announced tv schedule was just a suggestion of what they might put on at around that timeframe. Except Santa Barbara, people went mad if that wasn't on schedule :)