Forum:Thoughts on modded weapons

I play borderlands alot and recently i was invited to a game by a player, we killed crawmerax a few times, which got me to get the achievement on killing crawmerax. But back to the topic, after fighting Crawmerax, he duped me alot of pearlescents, some legit, but most modded. I am now wondering will anything bad happen if i keep using these weapons. I don't use them in online duels, i use them for farming with friends or anyone who wants to farm. And i dont steal every piece of loot when i enter some random guys game either. Will i get banned or something?