On National Review Online, Paul Howard of the Manhattan Institute warns against it:
The proposition [among other provisions] also makes "profiteering" by companies illegal. Profiteering is defined as "an unconscionable price" or an "unreasonable profit," terms that are so vague and open-ended that they would expose manufacturers to constant (and very expensive) harassment from plaintiffs' lawyers.
For more, see OL Oct. 26, Nov. 2. More: Proposition 79 (description) has mostly trailed in polls this fall, according to RealClearPolitics, but the "Yes" vote was within two points of the "No" in one recent Stanford poll. Ben Zycher, Steve Bainbridge and Bookworm Room weigh in. And three cheers for the L.A. Times editorial board:
Unfortunately, Proposition 79 overreaches in granting private attorneys the right to sue companies charging "unconscionable" prices without having to produce a client who has been harmed. Californians last year rejected such "private attorney general" suits when they passed Proposition 64, and 79 would chisel away at that reform.
[updated and bumped 9:30 a.m. EST]