That was not a good idea. While it can be fine, you need to know a few things:
amps matter less than voltage. IF it is pushing two amps at 5 or 5.5V, fine. IF it is pushing them at 7.4 or 10 V (like the ipad charger and a lot of tablet chargers), then you will have problems.
If your phone works, it limits the current to a safe level anyway, so chances you are getting an actual 2A are low. You may be getting 1.3A or something like that, or you may still only be getting 1A. However, once you over volt (which a lot of those 2A chargers do...I have measured really cheap ones to go to 6.5 or 7V to get 2A into a phone battery), you are done.
In general, unless all of the following apply, it is a bad idea to use them:
-you know your phone battery's emergency cutoff circuit and voltage overages for current works
-You know the charger keeps to the standard USB spec votage or a little above (5 to 5.5V is normal). Reading it is not enough...a lot of cheap ones are made to work at 5V but just do not because they are junk.
-You trust the maker of your charger enogh to have not lied in their specs.
Hpethat helps,
-Nkk