A container ship owned by Zin Lines of Israel was scheduled to dock at the port of Oakland in California on Saturday. Zin Lines is the biggest shipping company in Israel and is responsible for exporting a great deal of Israeli manufactured goods. Between two and three thousand protesters plan to form a picket line and are hoping to prevent the ship from being unloaded by dockworkers. According to this article, the ship paused offshore and was delayed at least 36 hours. Judging by what I am seeing on Twitter the ship is now moving toward the port, although it has yet to dock. The protesters see this as good news and believe that their actions are what have caused the ship to remain offshore. Googlefu tells me that a Panamax container ship (biggest ship that can transit the Panama canal) commands a day rate of between $9,000 and $10,000 per day, So this gives us an idea of what this protest is costing Israeli businesses (assuming the ship is only carrying goods from Israel). Protesters are performing this action in protest of the Israeli occupation of Palestinian territory, and the apartheid-like conditions within Israel.
In an unrelated note, I read today that people from Gaza have been sending advice for dealing with tear gas and riot police, along with words of support to protesters in Ferguson via Twitter.