Can you cite any cases where the ACLU did this?
Stipulated by lack of action. The ACLU has never defended the second Amendment. Only if there had never been an infringement of 2A could ACLU be relieved of this responsibility as the 2A IS a civil right.
Sure. Visit http://www.aclu.org/ . In specific, http://www.aclu.org/PolicePractices/PolicePractices.cfm?ID=9621&c=25
The ACLU claims they're "neutral" on anti-Second Amendment legislation, but they're actively in support of such unconstitutional laws.