A rally is being planned for free agent quarterback Colin Kaepernick at NFL headquarters later this month.  Several civil rights groups are organizing the rally, which is scheduled for August 23rd.  

Filmmaker Spike Lee tweeted an advertisement for the rally and added that he did not organize it but supports Kaepernick and "his stance on injustices in the USA."  Kaepernick made national headlines last season when he knelt during the national anthem to protest social injustices.  Many believe that's the reason he remains unsigned.

Photo: AOL