You know how, here in Israel at least, it is pretty common where you are in a shop or walking down the street or waiting for the bus and someone comes over and asks to use your phone to make a call. It is super common with kids needing to make a call but often happens with adults or young adults as well - maybe some people dont carry phones or maybe a phone battery drained, but it happens often enough. As long as I am not in a rush or out of sorts in some way, I will almost always let them use my phone. I think most people do. And if it is a kid, I will just about always allow it unless there are extenuating circumstances. .

So, Kikar reports that an avreich in Bnei Braq was standing outside a wedding hall when a young man (unfamiliar to him) approached asking if he could use his phone for a short call. The magnanimous avreich handed over his phone, as I think most people would do, and the fellow made his call.

A few days later the avreich gets called in to the police station and discovers he is being investigated and questioned due to a complaint of harassment. 

It turns out that this young fellow wanted to threaten someone and knowing he would be easily tracked had he used his own phone decided he would borrow someone else's phone to make his threatening phone call and thereby stay anonymous while framing someone else.

Somehow during the questioning the avreich figured out what happened, that it was the phone call he had lent his phone for and eventually convinced the police that he was telling the truth. The police let him go but because he didnt know the person he had lent the phone to, so they were up a creek though they eventually figured out who the caller was and brought him in (they eventually decided the harassment was not important,. low level stuff and will likely close the case. it was over a fight between two different hassidic groups)

As it says, the fake tzedaka collectors save us for not giving enough tzedaka out of concern the petitioner might be a fraud, so these phone scammers save us from not lending out our phones to people who need to make a call... though I guess this is not overly common so probably wont yet affect anything.