Google seems to come up with a lot of conflicting advice. There definitely seem to be people out there who have fed them, personally I would avoid it though for a number of reasons.
It is always best to be cautious when it comes to unknown foods as it only takes one mistake to have unpleasant consequences.
My reasoning behind not feeding them would probably be that they are not packaged, so are exposed to everything in that pineapples journey. They are also potentially sprayed with pesticides and unlike other foods that are treated in this way, (such as lettuce etc.) they are not intended for human consumption so are unlikely to have been washed after picking.
It is of course entirely your own decision, whatever you decide though, do it in moderation.