The parents of two graffiti artists jailed for spray painting trains and railway bridges are protesting at the length of their sentences.
Thomas Dolan admitted criminal damage last month
Thomas Dolan, 20, and Thomas Whittaker, 18, both from Macclesfield, Cheshire, caused about £13,000 damage.
Both admitted criminal damage at Manchester Crown Court and were jailed for 15 and 12 months respectively.
Denise Dolan said she knows her son did wrong but insists the punishment does not fit the crime.
More than 500 people have also signed a petition on the social networking website Facebook after the pair were sentenced last month.
The pair caused about £13,000 worth of damage
The men were traced after British Transport Police (BTP) tracked website postings of their work.
Dolan used the graffiti name, or tag, of Krek and Whittaker went by the name of Mers.
They were responsible for graffiti on trains, stations and railway property in Gatley, Bury, Buxton, Wigan, Macclesfield, Stockport and Longsight.
Denise Dolan has even offered to pay for the damage caused by her son.
Sentence a 'deterrent'
She said: "As parents, we offered to pay the money just to keep them out of prison, so that my son could go to university which he should have started this week.
"The British Transport Police just dismissed it.
"What they've done is against the law but the punishment should fit the crime.
"I've spoken to Tom and he said the prison wardens and officers all agree, they said they shouldn't be there."
A BTP spokesman said: "The nature of the punishment and the length of sentence were matters for the court and the judge to decide.
"The role of British Transport Police is to investigate the offences and gather the evidence.
"The fact that these two individuals received custodial sentences reflects how seriously the courts view graffiti damage and should serve as a deterrent for any potential offenders."