The rarity of Alpha Matter, heavy government regulation, and the relatively high cost of contracting the Structs Conglomerate to conduct mining operations, are some of the factors ensuring that there is dramatically more demand for Alpha Matter than there is supply. This demand has created a robust black market, where criminal factions and corporate saboteurs seek to acquire Alpha Matter through back channels.
Most reputable Guilds engaged in mining operations encode unique serial numbers on Alpha Matter reserves at a molecular level as a function of the refinement process. Although it is possible to expunge these identifiers, in practice, few pirates have access to the  equipment and expertise necessary to do so.
For this reason, most illicit acquisitions of Alpha target the less-traceable raw Ore. Pirates surreptitiously surveil the uncharted regions for Alpha Bases with large stores of Ore awaiting refinement as potential targets for raids.
Thefts or salvage of refined Alpha Matter do occur, particularly of lightly-armed transport vessels that require Alpha Matter to fuel their FTL drives, but incidences of large-scale theft have been dramatically reduced as most factions rely on Alpha Relay technology to transmit power, centralizing most reserves of Alpha Matter on heavily fortiified worlds.