Heck, I could cough once for buy, twice for sell. Who's going to surveil me and notice that?
Back when the stock market was founded, it was meant as a means of providing a signal of support for a company. It allowed the company to raise debt or financing based on it's stock price or signal of support. You bought company stock because you believed in the fundamentals of the business and you wanted to support it. Now it's just about how i can sell this stock to the bigger sucker, for more money than i bought it for.
Technical analysis generally uses only publicly available information; it's finding patterns in those publicly available data that can help you make investment decisions.
I'm not saying it's socially useful; just that it is distinct from insider trading.
Additionally, with hft data speeds matter and exchanges only allow co-location of servers to 'premier firms'.