"I'm sure everyday-Americans do it and get away with it"
Probably not. Insider trading often doesn't provide massive returns - rather smaller quick one off returns (think 10-20% next week). The key limiter is the person must have a good understanding of the market, a trading account (possibly allowing complex betting) and lots of MONEY
Are you prepared to go to jail for 10% of your savings? Would you be if your life savings were £1,000?