There is some bike stuff that is so bad that it demands a discard. For the betterment of society and the greater public welfare. This includes:

• Steel rims, or wheels with steel rims
• Dia-compe road brakes
• Any component that has been recalled or has a reputation for catastrophic failure.
• Bars or stems that have been crashed
• Bike frames on which you've spent days trying to remove a stuck seatpost or stem.

What I mean by discard is not any of the well meaning but potentially ultimately fatal acts:

• donating it to the bike coop or Sally Ann or whatever...
• leaving on your curb
• taking it to the local recycling depot

What I mean by discard is chopping them into unusable bits and discarding them deep in the trash. Trust me, removing useless and dangerous bike crap from circulation is a valuable public service.

Because if the stuff does find its way back into use, it will cause more safety, health and nuisance issues than the parts are worth - to any rider.

Weird old French, Italian or Swiss threaded bits.... if they are good, then bag them, label them and donate them. Or Ebay them. If they are cheap or worn out, chuck them. Do not blissfully dump them with the local bike Co-op as some newb bike mechanic will spend hours of frustration trying to torque an Italian cup into an English threaded frame, potentially wrecking his project.