If changes currently going through parliament become law, Asbos will become a tool in criminal cases, so people convicted of crime and disorder offences can be subject to an order on top of their sentence.

BBC: Q&A: Anti-social behaviour orders

Over-prosecution is a tool prosecutors often use to get criminal defendants to plead guilty rather than risk a more severe sentence if they go to trial.

FORBES: Aaron Swartz' Suicide Forces Hard Questions About The Criminal Justice System

Law enforcement has done criminal profiling for decades and recognizes it as an invaluable tool.

CNN: Screening must include religion, ethnicity

Since it became operational in 1998, the National Instant Criminal Background Check System (NICS) has been an essential tool in the effort to ensure that individuals who are prohibited under Federal or State law from possessing firearms do not acquire them from Federal Firearms Licensees (FFLs).

WHITEHOUSE: The White House