Let's of course ignore the nature of the blockade, and the affects it has on the people of Gaza of course. And let's also ignore the fact that just because rules are in place, that they are legitimate rules. Yes they violated certain rules that Israel wanted them to follow, but how does that make them "in the wrong" here.
I'm sure it wouldn't be too much of an exercise in history to find people "breaking the rules" being clearly right in their actions.
Do you think that the people of Gaza are glad that the rule of Israel was followed here? I doubt it.
As someone who has been involved in activism for quite a bit, this couldn't be more wrong. Usually the smaller protests are indeed a sign of the message of the protest, etc. etc. not being relevant. But many big protests (not all of course) certainly strike to the core interests of the protesters (good example was the union march on wall st.). Also the "Seize BP" campaign in the US South and around the country has quite a bit to do with people who are affected and concerned.
Granted there are some counter examples (big protests with people seemingly going against their interests) like the Tea Party movement. Although many on the Left will point to the class makeup of those demonstrations and the financial backing of that movement and the Tea Party begins to make sense.