Anybody who has FU money: start filing papers for a lawsuit against Yahoo and notify them of your intention to do so. Pay for expedited filing. This is the worst kind of PR for a company and they'll do almost anything to avoid being sued in the first place. A settlement offer is Not An Option.
Anybody living in the SF Bay Area, Especially if you live in the Silicon Valley: Pay a visit to Yahoo Global HQ. Find out the borders of their property, park and picket right outside them.
Anybody with the resources: Make / Print a banner that says something like:
yahoo! #WENEEDMORETIME! #YahooGroups
To drape over this pedestrian bridge located at [37.397547, -122.022673] https://goo.gl/maps/XknYg9H3BYWZPESF9 South Entrance Address: 101 E Ahwanee Ave, Sunnyvale, CA 94089 (Intersection of W. Ahwanee Ave. & Borregas Ave.) P.S.: A good alternate location is the US-101 Mathilda Avenue Overpass, on the sidewalk southbound / northbound (37.398832, -122.027722)