@farmerman,
I feel there are degrees of thermonuclear devices that should be considered here. First there are pulse thermonuclear devices and the traditional explosive type. Both types have application, consequently it would have consequence on this discussion.
Pulse- this could be a prompt nuclear event that is designed to give prompt nuclear events--Very short (microsecond duration) . In addition to the timing of the event you could have choice of type of radiation (alpha, beta, gamma, neutron), particle frequency, and degree of coherence (X-ray lasers) and energy yield.
As for application, it could be used for home protection. In one case I can imagine a security system connected to a small pulse reactor (thermonuclear in application) that could stop a invader (from stun to kill) upon detection. Another application as a pulse thermonuclear hand held X-ray laser that would be analogous to a Glock with a nearly infinite magazine.
Thermonuclear explosions--as anyone understands a modicum of physics explosions result from the expansion of matter. Chemically it happens when you have a very fast reaction (usually greater than the speed of sound in matter) yielding a sudden expansion of matter. With small thermonuclear events this can result from the sudden release of thermal energy. That is turning all matter in the vicinity of the criticality into a plasma.
OK here's the rub--explosives can be used for construction. And as such are a productive tool (unlike a conventional firearm).
As a result one could envision technologies that would have to be considered on the constitutionality of possession of small thermonuclear devices by individuals.
Rap