http://fellowshipofminds.wordpress.com/2013/03/29/police-tear-gas-and-beat-peaceful-marchers-supporting-traditional-marriage/

And just in case you're going to march,

https://www.google.com/webhp?hl=en&search=search#hl=en&site=search&output=search&sclient=psy-ab&q=preventing+effects+of+tear+gas&oq=preventing+effects+of+tear+gas&gs_l=hp.3...2430.7866.1.7984.30.18.0.0.0.0.2049.9864.3-1j1j2j2j2j1j1.10.0...0.0...1c.1.7.hp.0e3UGcJftdk&psj=1&bav=on.2,or.r_qf.&bvm=bv.44442042,d.eWU&fp=540ef120900339c2&biw=1272&bih=496