ready to persecute offenders

-- "No pranksters (local news briefs)" in Vancouver 24 hours on May 26, 2009

That's a little mean. Why not just prosecute offenders?

Dictionary.com's definition of persecute:
-verb
1. to pursue with harassing or oppressive treatment, esp. because of religion, race, or beliefs; harass persistently.
2. to annoy or trouble persistently.

Dictionary.com's definition of prosecute:
-verb
1. Law
a. to institute legal proceedings against (a person)
b. to seek to enforce or obtain by legal process.
c. to conduct criminal proceedings in court against.