[wiggles_md]

> With that background, the morality of "smuggling" these cells is a bit of a gray area.

The grey area here is from lack of foundational knowledge surrounding these cells, and your assumptions aren’t useful (nor are they likely, I suspect, to hold). For example, we have no idea if these cells were originally provided to the lab under an MTA, nor any restrictions placed by the funding source.

> Keeping them is just like me keeping my notebooks when I move, even if I haven't finished solving the equations therein.

This is not a grey area: lab notebooks and lab data are generally speaking the property of the lab. The proper procedure is to request permission to create a copy of them when you move to a new institution. Check your university’s IP policy, it should be the governing rule set.