From the article: "many, though admittedly not all, courts have held that contacting former clients regarding a change in employment constitutes a solicitation.

From the article: "many, though admittedly not all, courts have held that contacting former clients regarding a change in employment constitutes a solicitation. See e.g., Merrill Lynch v. Schultz, 2001 WL 1681973, *3 (D.D.C. 2001) (noting that “such initiated, targeted contact is tantamount to solicitation because there is no reason to believe that a customer on the receiving end of such a [communication] does not assume that the [employee] wishes for him to transfer his account.”)." This reasoning doesn't necessarily hold for linked in. If a person has lots of contacts on linked-in, some of which are customers and some of which aren't, changing your employment status isn't targeted, wasn't specifically initiated, and can't be assumed to be a solicitation.