Secret Service found letter mailed to President Obama laced with “suspicious substance,” more suspicious letters sent to senators, and now a Senate office building is on lockdown.

Six protesters were arrested by Capitol Police officers inside the Hart Senate Office Building this afternoon after attempting to unfurl a banner related to the Stop the Machine protest.

Roll Call’s Emily Yehle reports that some drunk guy managed to wander in and out and back in to the Hart Senate Office Building through a parking garage on Monday before finally being stopped by Capitol Police. The incident “appears to be a function of somebody not doing their job.” You think? The man, described as having “no malicious intent,” was eventually arrested for unlawful entry. Lots of hemming and hawing about human error from…