A Taiwan opposition politician was arrested for pelting a rival's campaign office sign with eggs, and lawyers say he could face years in prison — bad news for him, and a warning ahead of the local elections.

• New Party deputy secretary-general You Chih-pin used a megaphone outside DPP candidate Chang Chih-hao's campaign office, then threw eggs at its sign.
• Police arrested him on the spot for criminal damage.
• Beyond damage and public insult charges, the bigger risk is election law: trying to make a rival lose can carry up to five years.
• If convicted on several counts, courts would sentence him under the heaviest one — the election law charge.
• Without a settlement or a suspended sentence, he could get anywhere from a few months to five years.

Outlook: The case will test how hard Taiwan's courts punish campaign-season stunts as local election battles heat up.