You are correct that jurisdictions vary significantly.
But I believe the Massachusetts is pretty strict.
eg, here the legal department of a hiring company said the non-compete on a laid-off worker was probably enforceable:
Bob Balaban of Lexington took a software engineering job in 2008 that required him to sign a two-year noncompete agreement. During the recession of 2009, he was laid off. Balaban had several interviews with managers at a prospective employer, but it had a business unit that competed with his old employer. “They informed me that their legal department advised them against hiring me because of that
Courts find them enforceable, too:
And these cases do sometimes wind up in our court system, taking up judges' time. Earlier this year, a judge blocked a South Shore hair stylist who was fired from one salon from taking his blowdryer over to another salon.
The original article talked about New York, on the topic of New York non-competes:
"Editor: Doesn't much of New York law disfavor non-compete clauses in employment contracts?
Klein: The court cases do say that non-compete clauses are disfavored, but that does not mean that they are unenforceable. In New York, non-compete clauses in employment contracts will only be enforced to the extent reasonable and necessary to protect valid interests. The case that is most often cited for this standard is BDO Seidman v. Hirshberg , 93 N.Y.2d 382, 712 N.E.2d 1220, 690 N.Y.S.2d 854 (1999). In deciding whether a restrictive covenant is reasonable, a court will examine certain factors relating to the length and scope of the non-compete that bear on the employer's legitimate business interests and the extent to which the employee still can earn a living. Also, New York is a "blue pencil" state, so even if a covenant not to compete is too broad to be enforceable as written, a court has the power to modify it - particularly if the contract indicates that it was the parties' intention that the court be able to do so. In short, the recent case authority indicates that New York courts are enforcing covenants not to compete and benching employees when the legal standard is met."
I don't think 'being a summer intern' meets the standard but as we both are not lawyers we cannot say for sure. I know that I would offer to defend this guys if he got sued by his former employer but that is just me.
But I believe the Massachusetts is pretty strict.
eg, here the legal department of a hiring company said the non-compete on a laid-off worker was probably enforceable:
Bob Balaban of Lexington took a software engineering job in 2008 that required him to sign a two-year noncompete agreement. During the recession of 2009, he was laid off. Balaban had several interviews with managers at a prospective employer, but it had a business unit that competed with his old employer. “They informed me that their legal department advised them against hiring me because of that
Courts find them enforceable, too:
And these cases do sometimes wind up in our court system, taking up judges' time. Earlier this year, a judge blocked a South Shore hair stylist who was fired from one salon from taking his blowdryer over to another salon.
http://www.boston.com/business/technology/innoeco/2011/09/no...
IANAL, but I think your intuition might be dangerous.