The problem is, I really do believe any kind of mass support for the Iranian protesters will in fact be co-opted to start a war with Iran--at least at this particular moment in time.
And the executed protesters are a bad thing. But I don't think military intervention will lead to a better outcome.
Supporters of Palestine had pretty specific requests, none of which apply to Iran (conditioning weapons sales, divestment, etc...)
Also... Are the executed protesters not also death and suffering? What about victims and conflicts resulting from the groups Iran funds?