I was reading through some weed risk assessments for plants that are common in many aquariums on this page
USDA APHIS|Noxious Weeds Program Risk Assessments
There are not only banned plants but plants that are indicated to likely be pests including many that we may have in our tanks.
I know most of us are probably careful but some of these guys propagate from fragments or seeds so aggressively that they can present create major environmental headaches.
I'm thinking I will have to mulch or otherwise nuke fragments when I clean up my tank and just putting this out there to see how you handle this yourselves. I guess a lot of out aquarium plants could become problems so having a recommended dispose/destroy process is critical for each one of us.