Undercover journalism and prosecutorial discrection

Given the recent initiation of criminal prosecution against the people who made the defamatory video about Planned Parenthood, I thought I'd quote what journalism says about undercover journalism:

CJR:

Undercover reporting can be a powerful tool, but it’s one to be used cautiously: against only the most important targets, and even then only when accompanied by solid traditional reporting.

And Society for Professional Journalists:

Avoid undercover or other surreptitious methods of gathering information unless traditional, open methods will not yield information vital to the public.

So they're saying do it rarely, only when necessary, and do it well.

The prosecution against the undercover activists isn't for doing it badly, it's for doing it at all. It would apply equally to many groundbreaking investigations by true undercover journalists. And the line between journalist and activist is a slippery one that maybe doesn't matter (e.g., the people exposing animal cruelty at factory farms).

As a practical matter I don't see a good way to modify the law to say "don't use fake identification unless you're working undercover." That's where prosecutorial discretion comes into play. The grand jury has no role in that discretion and district attorney seemed to ignore her responsibility.

This indictment will be used to keep corporate crimes hidden. Go after these people for doing a bad job via defamation suits instead, but don't ban undercover operations.