Concerns were raised after 36-year-old Sinaga was publicly identified on Monday as the UK's most prolific rapist and detectives began receiving multiple calls.
The Indonesian student was jailed for life with a minimum of 30 years after drugging and sexually violating 48 men at his city centre apartment in Manchester.
Greater Manchester Police set up a dedicated incident room as their investigations established that 195 men in total appeared to have been unconscious when Sinaga filmed himself assaulting them, with 70 of those still to be identified.
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A spokesman said: "We are aware of a number of social media posts circulating which may identify potential victims of sexual offences in connection with the live investigation into Reynhard Sinaga.
"We would like to stress that, under the Sexual Offences (Amendment) Act 2000, victims of sexual offices have a lifelong right to anonymity and therefore any post which identifies victims of sexual offences constitutes a criminal offence.
"Additionally these posts risk jeopardising an ongoing investigation into serious crime.
"Please be mindful when sharing any social media posts."
Sinaga's trial heard that he went out in the early hours of the morning, hunting for lone, drunk young men around nightclubs near his flat.
The slightly-built student posed as a Good Samaritan who offered them a floor to sleep on or promised them more drink.
His victims - who were mainly heterosexual - had little or no memory of the hours that followed as Sinaga repeatedly raped many of them.
It is thought he laced alcoholic drinks with a drug such as GHB, also known as liquid ecstasy.
He was caught when one of his victims regained consciousness and fought him off before going to the police and, crucially, handing in Sinaga's phone.
Sinaga was found guilty of a total of 159 offences committed between January 2015 and May 2017 - 136 counts of rape, 13 counts of sexual assault, eight counts of attempted rape and two counts of assault by penetration.