Police are investigating a coordinated attack on at least 17 Starbucks outlets in downtown San Francisco. Police say vandals spread glue and attached printed “For Lease” and “Closed” signs on store windows late last night or early this morning. The Seattle-based company confirms that eight stores were vandalized. Starbucks officials say there were no injuries or serious property damage, and all the stores are open for business as usual. Nobody has claimed responsibility for the vandalism, but police believe it was a carefully planned attack by a group. Police are questioning one possible witness and are encouraging others to report any information they have.