While celebrities and some other people were quick to condemn the shooting of Cecil the Lion, human rights activists decried their lack of sympathy for the growing list of African-Americans who lost their lives due to racial discrimination in the US.

Writers and personalities expressed their disgust over American netizens' easy outrage against the lion's shooter, Walter Palmer, which they said was more intense than their reaction to the death of innocent black people at the hands of abusive and trigger-happy police officers.

"Laments for Cecil were, sadly, much more heart-rending than the outcries for black lives lost. Uproar over the famous lion's death almost instantly reached the late-night talk show circuit," a Huffington Post article said on Thursday.

"It seems like Americans, in general, found it easier to condemn a man who killed a lion than to criticise police officers who abuse their power," it added.

Huffington Post reporters Julia Craven and Kim Bellware noted that it took more than six months before charges were filed against a Cleveland officer who killed unarmed 12-year-old Tamir Rice who was playing at a park.

"It's sad that the death of a lion is bringing more tears than that of many a human being simply because those people weren't white," Craven and Bellware said.

Writer and activist Luvvie Ajayi made a sarcastic remark about Jimmy Kimmel for crying about Cecil the Lion, saying: "Who else has he cried for or is that level of sadness reserved for murdered animals? I'll be here waiting."

Writer Roxane Gay took to Twitter to ask if black people would get more concern if they dressed like lions.

"I'm personally going to start wearing a lion costume when I leave my house so if I get shot, people will care," she posted, according to CNBC News.

Republican presidential candidate and Florida Senator Marco Rubio used the reaction over Cecil's death to attack Planned Parenthood.

"Look at all this outrage over a dead lion, but where is all the outrage over the Planned Parenthood's dead babies?" Rubio asked, referring to the spate of anti-abortion sting videos that saw Planned Parenthood employees discussing the harvesting and sale of baby organs.

There is also some backlash building up on Twitter with several users wondering about where the celebrity passion has gone for Sandra Bland or the Black Lives Matter movement?

Howard Bragman, a veteran Hollywood watcher and CEO of Fifteen Minutes Public Relations, explained that celebrities respond to animal stories like ordinary people, clarifying that it has the added advantage of being less controversial than racial discrimination issues.

"Animal activism has always been a staple of Hollywood activism, it's really in the DNA. Celebrities have found when they step into some of the race issues, they've gotten their hands slapped for perceived insensitivity, even when they were trying to do and say the right thing," Bragman said.

"They realise that animal activism is a win-win. In most cases, nobody objects and particularly in this specific case," he added according to USA Today.

Some tweeters, however, wish more celeb passion could be directed at the case of Bland, who was jailed after a traffic stop in Texas and ended up dead in her cell.

By contrast, one online petition demanding justice for Bland only has a little more than 6,000 signatures at the moment.