A rights group has said an American man, who posted a parody video about youth culture in Dubai, was being held by the authorities.
Shezanne Cassim, a 29-year-old registered in Woodbury, Minnesota, was the first foreigner arrested under tougher measures governing use of the internet in the United Arab Emirates.
The London-based Emirates Centre for Human Rights said the Sri Lankan-born Cassim was arrested in April after posting a video in 2012 poking fun at how many youths in the region were in awe of the power of social media.
Cassim was charged under a 2012 cybercrimes law boosting penalties for content which is perceived to challenge authorities.
The US embassy had no comment.
Family spokeswoman Jennifer Gore said that Cassim's relatives decided on Wednesday to make the case public.
Another man was arrested earlier this year after he filmed and uploaded a video showing an Emirati man slapping and beating an Indian expatriate van driver with his igal, or headband, on July 13.
The case has sparked a debate over strict national laws on filming public scenes and people.
Using Twitter, Dubai police announced officers had "arrested the man who shot the video of the bus driver incident".
Dubai police told local media that an Emirati man had also been arrested for the attack.
Responding to a question on social media from an Australian expatriate in the UAE over the law, the police said the cameraman was arrested "because he shared" the video.