Terry "Lil Wood" Sillers went from being a general in the Aryan Brotherhood of Texas (ABT) to being smashed off the yard at FCI Beaumont by a bunch of younger ABTs that got sick of him, so he decided to get back at the gang by becoming a rat. Eventually several ABTs received combined sentences of over a thousand years because of what Sillers had to say. He probably started telling on people the second he got smashed off mainline in Beaumont because his next stop was FCI Forrest City, a low security prison. The only way an ex-ABT shot caller like him could be considered for a low would be if he told on someone. Rats are typically sent down to lower security prisons because the extra freedom is viewed as a reward, but mostly because at a low the other inmates are not likely to kill him. Low security prions are full of lames that are usually rats, white collar criminals, non-violent sex offenders, or just guys with good behavior that won't put in work.
Once he was released and could not find a job he snapped, went on a high speed chase on a motorcycle (see video below), and after getting caught became a full blown informant. He told on everyone he could think of over anything he could remember, got just 10 years despite his record, and should be out soon. Once he gets out then he will really have to worry about his safety because the walls of the low can't protect him anymore.