CNN has a couple of bad questions posing as headlines on their web site
"Is it ok to be racist outside of school?" No. Is it legal, all else being equal. Yes.
The essay dealt with MA kids whose tweets racially dissed a black Washington player after he knocked Boston out of the NHL playoffs; their school is disciplining them for their extracurricular behavior, which the essayist noted is of dubious First Amendment legality.
Lots of things are legal and even constitutionally protected, but not OK.
Are we seeing a 'Mexican Spring'? No, you're just seeing the Mexican left using social media. The Mexican Spring came a decade ago when the PRI allowed itself to lose to the right-of-center PAN; now, the PAN has spent a decade-plus in charge and has lost its freshness and the race for president is between the establishment-left PRI and the hard-left PRD (Canadian Liberal versus NDP might be a fair comparison if you had Howard Dean off his meds heading up the NDP; letting Canada annex Vermont is always worth dreaming of).
Last go-round, the PRD candidate, Andres Lopez Obrador lost a squeaker to the PAN candidate and protested like crazy even after a recount confirmed a Calderon win. Lopez Obrador is heading up the PRD ticket again, and has Mexico's noventa y neuve por ciento hot and bothered like a 2008 version of Obama; since Lopez Obrador's party has never won the Mexican presidency, he looks like the pristine outsider.
Yeah, you have leftist youth using social media. Youth use social media unless they are totally dirt poor these days. However, Mexico in 2012 isn't a unreformed dictatorship in need of a peaceful revolution; Mexico 2018 might be if Lopez Obrador gets in.