The force monitored postings by youngsters on sites like Bebo
The comment comes after Central Scotland Police interviewed 182 children, aged between 12 and 18, about illegal online activities.
As a result, several youngsters have been reported to the procurator fiscal and the children's panel.
More than 70 youngsters have also been deemed "vulnerable persons".
In a crackdown on anti-social behaviour, the force monitored postings on Bebo and found references to crimes including substance abuse, racism and weapons possession.
Other intelligence was also gathered relating to drug-dealing activities.
Officers visited the homes of 80 youngsters in Falkirk, 37 in Clackmannanshire and 88 in Stirling.
Assistant Chief Constable Derek Penman said: "In many cases the parent or guardian was simply unaware of their child's use of social networking in this way and reaction ranged from shock to disgust.
"In some cases sites were accessed in the presence of police officers and immediate access to the internet or the computer were withdrawn."
He added that the authorities would continue to monitor the situation and further visits to young people were planned.
In a statement, a spokeswoman for Bebo said: "Unfortunately, anti-social behaviour is an aspect of the society we live in.
"Content which comes to our attention that contravenes those terms is immediately suspended and investigated.
"We educate our users to be responsible and to understand that they are not anonymous online as their activity creates a digital record of behaviour which, should it breach our terms, can be used to assist law enforcement if required."