This is the sign. Note the source attribution at the bottom.
The vidoe is unbelievable...the officer was (IMHO) intejecting his own political feelings and opinions of the poster into a exercise of 1st amendment rights on what appeared to be public property.
Folks should watch the video. It is indeed a poster created from my site:
It's the latest one. Really is bringing them out of the wordwork.
Cooments at the yourube site indicate that the officer is Fairfax County Public Schools Security Services.