I have a friend who recently started sweeping and she, for awhile, did the bogus phone number. It's true, if anyone wants your number they can find it on the web. I think it's pretty safe with the big brand names.
I had another friend who is skeptical of entering and this morning said "aren't you afraid of giving out your info?"....I said, no, because I'm not giving them anything that anyone couldn't find on the internet anyway. I WILL NOT give out a SS # or a Driver's License Number, no matter what. I don't like to give out my cell phone either, and don't usually enter those that require it.
If you use a fake phone number, you really are disqualifying yourself, which it seems to me, might be a waste of time entering.