My kid was suspensed for 3 days for a much lesser offense which allegedly involved a poster with the word "butt-fucking" in it. He claimed he was not personally involved in this particular poster (although he knew who did it) but placed other posters calling for the retrial of Mumia abu Jamal - and alleged that his suspension was the retaliation for those other posters. Maybe. But thusly a valuable lesson has been learned - do not do stupid things while doing a political protest. When I was going to demos, organizers reminded everyone to get rid of any potentially compromising items (such as weed).
Cross hair can be construed as encouraging assassination, and that is illegal. You cannot publicly advocate the assassination of political figures or anyone for that matter. That kind of juvenile pranks only discredited a serious message.
Btw, a few weeks ago there was a media report that a Greyhound bus driver was arrested for saying to passengers "I am taking you to the Taliban." The sentence was uttered when some passengers started an argument with the driver over his attempt to find an alternative route to the congested NJ Turnpike. The passengers angrily questioned whether the driver knew where he was going to which he gave the reply in question. Some passengers called the cops who descended on the bus and arrested the driver.
Things like that were said to happen under Stalin (also, children ratting on their parents were openly praised by the media, just as the US TV does today) - but during my days in Eastern Europe people were openly criticising government in public places without fear of any retribution. This shows the true face of the Amerikun "democracy."
Wojtek