The following message (includes a video) has been widely circulated on the internet and on social media, it warns people not to hold or carry items such as water bottles for other people when in airports as it may contain illicit drugs.
AT AIRPORT, NEVER HELP ANYBODY BY HOLDING EVEN FOR A SHORT TIME, HIS OR HER WATER BOTTLE OR Anything else. This warning has come from an officer working at the airport. If you happen to buy a water bottle at the airport, please check the bottle. BEWARE of fake water bottles. Be careful !!!!
At the airport or close to any customs service, never accept or help somebody to hold his/her bottle of water or other objects , even for an elderly person or a pregnant woman, You could be arrested for cocaine or illegal drugs possession. In Singapore/Dubai, that means the Death Penalty !! Tell them to put the item on the floor or at any other place…
Watch this video/clipping (shared by the US Customs) to understand. Drug/Cocaine dealers are very smart people.
While it may not be completely true and it looks unlikely that you could be arrested simply for briefly holding someone else’s water bottle, its better to be cautious and use common sense while travelling. If someone (stranger or even an acquaintance) asks you to carry ANY item across a border while travelling, you have to be cautious. Also, its better to keep a close eye on your luggage and carry-on bags.