keeping contact information is probably against his contract, and covered as customer information under noncompetes
discovering an interest in being linkedin friends with them is not afaik
Yeah, I was suggesting the latter. The purpose of a non-compete is to keep him from taking information to the competition, so if he merely uses his phone contacts list to get a job, I don't think HP's going to sue.
In his shoes, I'd also make sure I keep contact information for all his best customers. Because if he gets laid off suddenly, he'll want to go back to them at least to say, "Hey, do any of your vendors need a reliable field service engineer?"