In the criminal sense a snitch will provide information to the police or feds in order to obtain lenient treatment for themselves and provide information over an extended period of time in return for money or for police to overlook their own criminal activities. Quite often someone will become an informant following their arrest.
A snitch like Brian Kasaine is not the innocent person who has a serial killer living next door so he tells the police to get the trash out the comm unity. A snitch is one who is selling dope (for instance) or doing some other wrong doing and gets caught but instead of taking their punishment like a man they tell the authorities info on other criminals so they can get off scott free or reduce their own punishment. That is a snitch! Jay-Z pays tribute to his friend Emery Jones who didn't snitch on him back when they were selling drugs together. He has sung a song "Ride with Me" featuring John Legend, after that man was jailed for 11 years. And now he's part of Jay-Z empire as Creative Director.
Yours truly Cyprian Nyakundi has never snitched on anyone. I protect my sources. Sometimes Bob Collymore wanted me to provide my Whistle-blower, by sending cops to threaten me, even with guns, but I told them to go fuck themselves.
Brian Kasaine should be shunned. If you see him, bully him. Let us not aspire to get such female traits as snitching. Rise up boy-child!