Christopher Hay, 22, was the first person to be charged under the Offensive Behaviour at Football and Threatening Communications Act in 2012 - after writing a message on his social networking site the day the act came into force.
Chip shop worker Mr Hay, from Kirkintilloch in East Dunbartonshire, posted a message that included a line saying: "I should've planned my parcel bombs better."
The comment was posted during the high-profile parcel bomb trial at the High Court in Glasgow.
Hay claimed it was a "throwaway comment" not intended to be seen by Lennon.
A a trial at Glasgow Sheriff Court he denied intending to cause fear or alarm or being reckless as to whether he did or not, and was found not guilty by Sheriff Stuart Reid.
While the sheriff branded the comment "an offensive and threatening communication" he said that, after considering all of the evidence, there was not the necessary criminal intent needed for Mr Hay to be found guilty.
The court heard that, during a police operation, the post was spotted using keywords on a search facility of Twitter.
When interviewed by police, Mr Hay admitted posting the comment on his social networking site.
The court heard Lennon's name was not mentioned and it was not directed towards him.
Mr Hay told the court: "It was a moment of madness."