The Advertising Standards Agency has cleared two ad campaigns launched by BT.
The first featured Dragons' Den presenter Peter Jones at the centre of Gremlin-caused mayhem.
It showed Jones in a darkened office before the little green monsters emerge and start chewing through cables and causing sparks to fly.
Eleven people complained that the ad was scheduled too early as it could be seen by young children who could be frightened by the Gremlins.
Some even claimed that their children had suffered nightmares as a result of seeing the ad.
The Swarm advertising agency, which created the ads for BT explained that, in the context of IT, the word "gremlin" was widely used to refer to an IT problem hence the campaign.
The ASA said that the Gremlins' antics were likely to be seen as funny rather than threatening and also that the ads had been timed so that they did not air around and in between programmes aimed at kids.
A second ad was also cleared.
This showed a mother and daughter arguing over the girl's constant use of the Internet, in which the mother said that she was worried her child was becoming a "geek" rather than worrying about security, because the family had BT's internet parental controls.
The ASA received complaints that the ad encouraged or condoned parents' letting their children use the internet unsupervised.
The ASA concluded that the ad was not in breach of any of its regulations.