I get a lot of the same thing on my team now, it is either the paint, or trying to find ways to "legally" tip other robots, or ways around the rules... but for me, I can chalk a lot of it up to us being a rookie team. My kids/mentors haven't seen the true spirit of FIRST yet...
So are your people new? if they are, I would say just hold on until the first competition when they really see it. They will most likely get it.
If they arent new, well then I would question your team's methods of portraying the message. At competition, have those kids go talk with other teams, help out some rookie teams, or teams that are having problems. Show them that on CD, nearly all the teams share their ideas. We are trying to share and help eachother, rather than just win the game. In the end we all end up with cooler more advanced robots because of it. Show them something on your robot which was copied from another team, then explain that it was "given" to you, rather than you "stealing" it. They need to see that it is much more gratifying to win based on a good strategy or good drivers than it is to win by knocking someone over or confusing another robot. But there are some people who may just never get it. Just dont let them affect anything that would change your strategy or color... put them on other tasks where they can be more useful, but less malicious
Maybe years down the line, once all of us have really figured this vision thing out, it will be cool to try to confuse everyone else's robot, just for the challenge of overcoming it ourselves... but I agree, with this being the first year, lets just all get it working, and then next year play around with more defensive manuvers.