As it tries to ramp up public pressure against cleaning companies, the union seeking a new contract for 3,200 Houston janitors is meeting impediments it didn't face six years ago when it won its first contract.

The Service Employees International Union has expanded impromptu strikes at the large office buildings its janitors clean. It also has disrupted meetings and has conducted traffic-blocking demonstrations that have led to 18 arrests as it seeks to increase what it calls "street heat" against business owners and cleaning contractors.

More at source: Chron.com