If it was made in sweatshops or by child labor do not buy it. No article of clothing is worth supporting companies who exploit people.
Here are some popular clothing companies that use sweatshops/child labor:
Forever 21, Urban Outfitters (also anti-gay marriage aka human rights), H&M, Victoria's Secret
Shocked, right? There are more companies that use unethical ways to get their products massed produced, too. I know it is really hard to know where your goods come from but it is our rights as humans to choose morals over fashion. Cruelty free is ALWAYS THE BEST OPTION. No top or shoe is worth another human's pain and suffering.
Also, everything Forever 21 sells is tacky as fuck. Please everyone for the love of God stop shopping there. PLEASE. Just stop.