According to NRG, "a number" (which could mean anything from 2 up) of Haredim in Ashdod have smashed their cellphones with their feet and with rocks, after a psak by Rav Wosner that it is forbidden to own cellphones because of pornographic downloads was read in their shul. (It's unclear from Ma'ariv's wording whether he also said they should be 'broken' or whether that was an embellishment by the people reading the psak). Cellphones, apparently, were also banned for the same reason at some large Rabbinical conference in Jerusalem on Motzai Shabbat, although NRG does not say exactly who attended.
This, of course, is an old battle, but the assumption has always been that it's a losing one. Still, if you do decide to get rid of your cellphone (or wig....) for religious reasons, the question is: why do you have to physically -- and violently -- destroy it? Why isn't it enough to throw it away, or sell it and never buy another one again? The cellphone itself is not bad, it's how you use it.