#BBCtrending: Nigeria's plea to #BringBackOurGirls

The BBC Trending team is always on the lookout for trends gathering momentum on social media around the world. Here's a selection of the trends that have caught our eye this week.

The abduction of more than 200 school girls in Nigeria last week is trending in the country today. Thousands have been tweeting the hashtags #BringBackOurGirls and #WhereAreOurDaughters in an effort to exert pressure on the authorities to rescue the girls, who were taken by suspected Boko Haram militants. Some of the girls escaped. Nigerians want answers about the whereabouts of the remainder. They've also used Twitter to urge the government and the army to take more action. "#BringBackOurGirls to restore confidence," tweeted Kayodeojutaiye, an economist based in Abuja. "The capability of our government to protect us will be in doubt if they don't".

Today marks a year since more than a thousand workers were killed when the Rana Plaza factory collapsed in Bangladesh. As part of a drive to keep the spotlight on standards in the garment industry, people have been tweeting the labels of their clothes using the hashtag #insideout. It's a way of questioning the fashion supply chain and asking where the clothes came from. Within 24 hours there were 15,000 #insideout tweets were posted. To mark the anniversary of the Bangladesh tragedy people have also been tweeting #RememberingBangladesh.

Is one wife ever enough? A prominent cleric in Saudi Arabia seems to think so. But he himself has four wives and his comments have prompted a heated discussion on Twitter. Salman Al Aoudah posted a video on his Keek profile, where he calls on men not to abuse the right in Islam to marry more than one woman. The video entitled 'One wife is enough' has been watched 108,000 times, liked almost 4,000 times and commented on almost 3,000 times. And that's just on Keek: Al Aoudah also shared the clip with his 4.6 million Twitter followers. The remarks are seen as quite significant because clerics don't typically speak publicly against polygamy in Saudi Arabia. As expected it provoked a robust debate about polygamy. An Arabic hashtag which translates as #OneWifeEnough was used more than 11,000 times since Monday. The hashtag was also used with irreverence. Yossef in Jeddah wrote 'the more the merrier' while Abdullah in Montreal tweeted an image with the message: "Add wife ... have life."

Compiled by Anne-Marie Tomchak

Do you know more about the above stories? What's trending where you are? Get in touch with us on Twitter @BBCtrending or email trending@bbc.co.uk