First off, I for one believe that they have the right ot punish anyone
who buys an illegal venom, as otherwise, it would be prtty powerless.
Second off, you do not have the right to punish someone who buys a
health vial. That falls under the jurisdiction of the Druid and Sentinel
guilds, as they are ones who make healyh vials. The Shadowsnakes are
controlling what their skills allow them to make. You would have the
right to punish anyone who bought armor or weapons from someone IN YOUR
GUILD, but not else, as the Paladins also make armor and weapons.
Now, if your two guild were to make a treaty between them restricting
the sale of certain arms and armor, which allowed for the punishment of
people who bought the illegal ones, THEN you could punish someone for
buying them, but not until.

Rand Al'thor.

Penned by my hand on the 18th of Chakros, in the year 54 MA.