I'll try and keep it short.

When Crocodiles (or many other wild animals) are fed by humans it causes a change in their natural behaviours. One area of concern is migration of additional animals into an area that traditionally only supports a limited number due to the availability of food. Crocs are territorial and generally setup their territories based on the available food supply. The more food, the more the area can support without conflict. When food supply is diminished territorial disputes occur with the smaller, weaker and oldest of animals being pushed out of the area first to find new food sources.

What is already happening in the lagoon is that, thanks to the readily available food supply, more Crocs are moving into the area as the territory of the original Croc's diminishes; as they don't have to defend the territory as vigorously. This will have a spiraling effect as other Croc's move in to fill the territorial void created by the migration to the food source. At some point in time though a critical mass will occur where the feeding situation created by humans will not be able to support the population. At that time there will be territorial conflicts and the Croc's will become more aggressive in their feeding behaviour.

Unfortunately we have already reached a point where stopping the feeding is going to have a negative impact. The Croc's at the lagoon will now have to migrate to find food sources. Due to their desensitization to humans and the association with humans providing food this will cause significant problems. Croc's that have been fed and desensitized will have no fear of moving into local residential areas on the lookout for easy meals (read small animals and possibly unwary children.)

When this happens, guess what's next. The only solution will be to kill off the Croc's in the lagoon that have been fed and desensitized. That is why the laws are in place to prevent direct interaction between humans and protected species.

A couple of citations regarding feeding programs:

http://www.thylazine.org/gallery/jumpcroc/

"Many of the crocodiles seen from the cruise had missing limbs. This is due to the abundance of domesticated food provided to the animals. The result of these daily feedings is that the section of river where the cruise takes place becomes overcrowded and crocodiles start to predate on each other."

http://jrscience.wcp.muohio.edu/fieldcourses01/MarineEcologyArticles/Draft2.AlligatorsoftheEve.html

"Florida law prohibits feeding of wild gators, as most fatal attacks on humans have occurred when gators have been fed by humans or are protecting their nests."