I have a couple of corrections and additions - The correct law verbage was referenced, but the wrong or different RCW number. I pulled this from the rcw web-site a few moments ago. Thanks for starting this thread - I just went to the web-site to print copies that showed
www.leg.wa.gov siting where I took the information from. This way if there were some sort of dispute over the information or an officer that disagreed with my point of view - at least my references would be accurate. Anyway, I had difficulty finding one of them, but found it in a slightly different spot. I also found a copy of the RCW that shows that it is illegal to post no hunting signs or no fishing on signs they don't own or lease.
see the three RCW's below:
http://apps.leg.wa.gov/RCW/default.aspx?cite=77.15.210RCW 77.15.210
Obstructing the taking of fish, shellfish, or wildlife — Penalty.
(1) A person is guilty of obstructing the taking of fish[, shellfish,] or wildlife if the person:
(a) Harasses, drives, or disturbs fish, shellfish, or wildlife with the intent of disrupting lawful pursuit or taking thereof; or
(b) Harasses, intimidates, or interferes with an individual engaged in the lawful taking of fish, shellfish, or wildlife or lawful predator control with the intent of disrupting lawful pursuit or taking thereof.
(2) Obstructing the taking of fish, shellfish, or wildlife is a gross misdemeanor.
(3) It is an affirmative defense to a prosecution for obstructing the taking of fish, shellfish, or wildlife that the person charged was:
(a) Interfering with a person engaged in hunting outside the legally established hunting season; or
(b) Preventing or attempting to prevent unauthorized trespass on private property.
(4) The person raising a defense under subsection (3) of this section has the burden of proof by a preponderance of the evidence.
[2001 c 253 § 30; 1998 c 190 § 24.]

& the next one can be found at this link
http://apps.leg.wa.gov/RCW/default.aspx?cite=77.15.212RCW 77.15.212
Damages due to violation of RCW 77.15.210 — Civil action.
Any person who is damaged by any act prohibited in RCW 77.15.210 may bring a civil action to enjoin further violations, and recover damages sustained, including a reasonable attorneys' fee. The trial court may increase the award of damages to an amount not to exceed three times the damages sustained. A party seeking civil damages under this section may recover upon proof of a violation by a preponderance of the evidence. The state of Washington may bring a civil action to enjoin violations of this section.
[2000 c 107 § 238.]

And here is the one that I really like that I found by accident -
http://apps.leg.wa.gov/RCW/default.aspx?cite=77.15.220RCW 77.15.220
Unlawful posting — Penalty.
(1) A person is guilty of unlawful posting if the individual posts signs preventing hunting or fishing on any land not owned or leased by the individual, or without the permission of the person who owns, leases, or controls the land posted.
(2) Unlawful posting is a misdemeanor
These would be the people that are
