My general feelings on protests and rallies are that the people involved in them are generally idiots up to no good. There are exceptions of course--notably the protests sweeping the Middle East earlier this year, and the protests that achieved the passage of Civil Rights laws in the '60s. But by and large, protests fall easily into the trap of giving the most visibility to the crazies and ultimately alienating most observers.
A good example is the anti-Vietnam war protests, which rather than bringing an early end to the war instead resulted in getting Nixon elected (twice) and dragging the war on for long past when the protests were over and the college kids went on to having wife-swapping parties and macrame lessons. The anti-Iraq War protests if anything helped Bush get re-elected, and even our Nobel winner-in-chief still has us fighting over there 8 years later. And the Tea Party protests of the past two years are (I believe) ultimately going to result in far greater economic ruin for this country as people like Michele Bachmann get treated as serious contenders for the presidency, lowering the bar for crazy.
In any of the above cases, I think it would have done the protesters some good to better organize their forces into providing a coherent argument and weed out the nuttier among their followers. Having a sign comparing Bush to Hitler or waving the flag of the Viet Cong or telling people that Obama is a slaveowner and taxpayers are slaves just makes anyone watching TV--who might otherwise agree that a war is a bad idea or government is hopelessly bloated--just say "ok, you lost me" and go back to watching Two and a Half Men.
The latest protest-movement-gone-wrong is the parade of hipsters and freaks camping out on Wall Street. In a world beset by serious financial panic--the Euro looking to collapse, the U.S. economy in a slump and a government in serious need of painful cuts--it's understandable to be angry at those who seem to be taking massive profits while the majority are suffering stagnant wages and high unemployment. But how to fix it is no simple matter--if a certain set of policies could fire up the economy with certainty, those policies would have been pursued, by Bush or Obama already. And what the government has already tried--from spending and tax cut stimulus to pumping cash into the economy via the Federal Reserve--hasn't worked. Stripping down executive compensation from highly profitable financial firms might make a few people happy, but for the life of me I can't see how this is going to help regular folks.
I note that a lot of the protesters are debt-ridden college graduates and current students, many that were interviewed owed upwards of six figures on their school loans and had no job prospects. While I certainly sympathize (having carried a high debt load myself when I graduated) I cannot understand the anger being directed at Wall Street--presumably, as the lenders behind these school loans. It is the colleges that consider it acceptable to charge over $40K a year for tuition, the lenders are just enabling you to pay for it on credit. Shouldn't the protest be taking place at the campus?