Yes.  The British did perpetrate the beginning of the slave trade in the US for sure.  However, we maintained the practice over a century later, and it took a bloody Civil War to end it.

The British, Western Europe & others may have legitimate reasons for banning the assimilation of "Hate Groups".  Sometimes I wish we could do that here.  However, I fear a very slippery slope if we ban the gathering of such groups here.  If we banned them from marching, liberals better watch out also.  The next thing u know a Conservative govt could "ban" Gay Pride marches here under the same pretextes.  Be careful what u ask for, etc., etc.

Lastly, concerning the success anti-Gay forces have had in getting out the popular vote against same-sex-marriage:  I foresee a day, maybe not in our lifetime, the courts will intervene on behalf of "marriage equality", or people's hearts will change when the truth really comes out.  It took court orders in the 1960s to end segregation (and, yes, I believe in activist judges when popular vote usurps equality as it did w/ Jim Crow in the South).  "No lie can live forever, sd. MLK  in the '60.  But, I concede they can last a very long time.