Will said:
I voted yes. 'May' implies that you want to do something, whereas 'can' implies that you aren't sure if you're able to do it.
There is nothing wrong with using "can" to ask permission to do something. It would be obvious enough given the context what is meant by "can".
"Can I use your bathroom?"
"Can I have a glass of water?"
"Can I use your telephone?"
Surely, you would not think that the speaker that asks these questions is unsure that he or she is able to actually "use your bathroom", "have a glass of water", or "use your telephone". I don't know. Maybe you'd misunderstand those questions? I don't think anyone else would.
There is nothing wrong with using "can" for permission or a request. "Can" is used for ability, to make a suggestion, to request something and to ask a permission.
One can use "may" for a request or permission if one so desires.
We can also use the negative form of "can" to emphasize that we think something is not so or that we are very surprised about something that is so.
"It
can't be snowing again!"
"This
can't be chicken! It has to be turkey."
