I was just reading about the very unfriendly, industrial-strength "no tresspassing" signs that have gone up at the Fullerton station platforms. The signs are very hostile looking for a public space.
It made me think of Amtrak stations where citizen volunteers keep an eye on the property and offer a welcoming presence to the public.
For example, I understand that the station in Lacey, Washington has an all-volunteer staff. Here is a link to news article about the Lacey station 25th anniversary: [
www.theolympian.com]
So rather than put up hostile signs that threaten you with arrest, couldn't the City of Fullerton employ a volunteer watch the property? Probably some people within the railfan community could even be found to do the job.