motorcycle riding practice in public school parking lot? why not?

[Dan]

Hey guys, I have a permit for motorcycle and Is it legal to practice in school parking lots?

today, i was practicing where no cars were parked and it was free space but one of the cleaner noticed and told the security guy at a school parking lot. It was around 4pm and no cars were parked but there were some cars, far away that were coming for soccer practice. This is huge lot. Anyhow, the security came and had no reason and told me I can't practice. I was doing just manuever with cones.. there was no students nor cars. I was in the middle of the lot and why can't i practice there? any problems or do I need permission to practice in empty parking lot? why don't people bother their own business...
Simply, 1/ there were no one in the parking lot but me
2/ some students were from far at the school door in the building. I'm very far from them
3/ it's big parking lot and i was at the back
4/ some cars come and go to pick their kids
5/ the person that reported seems like a guy with little truck that cleans the school
6/ security just came and said, you can't practice with no reason.
7/ What problem am i causing there. it's empty ...just because the guy felt like i'm practicing there, he is just felt like reporting me and now the security guy just has to say things to me...Help.

It's public parking,,do i have a right to practice there. I can't ride in public road yet as this is only place to practice my skills and being responsible.

[FlashDarkness]

It's a liability issue. If you crash, you could sue the school. That's the society we live in now unfortunately.