The internet is an important resource for information and communication. The internet in this location was pretty poor when this was written. It has been significantly improved since then and is currently operating at 1.52 MB/s.
This green symbol drawn on a library stool is commonly associated with anarchists. Why it is on a stool in a library I have no idea. What it tells me is that anarchists need books on the top shelf!
This person writes LEGALIZE TODAY. The fact that the note appears in all caps shows that they felt strongly towards whatever it is that they wanted legalized. Providing modern context to these words it is likely that the individual was referring to gay marriage or medical marijuana.