Official wording as follows
13. By ECB ruling, the use of any cameras, mobile phones, computers and other electronic equipment, for the recording, transmission or communication of match details, statistics, images etc is not permitted other than with the proper accreditation.
So theoretically they could get a bit grumpy with you using mobile phones.
In my experience, if you’ve got a phone, point and shoot, or even a small SLR you’ll probably be OK. As soon as you get out the big dog SLR with a lens that looks like you’re in competition with the the professional accredited media you’ll get some trouble.
I’d leave the camera at home. If you really want to take some cricket photos head down to your local club – they would probably appreciate some half decent match day photos.