Simplysafe systems can be easily hacked

Short answer: yes but not worried.  Why? use the search function www.simplisafe.com/search    The article has been discussed at length.

And they just came out with a new system using encryption for all signals.

When the problem was discovered, they indicated that there would be an upgrade path.  When they released the new system which fixes the problem, they said there was no upgrade path,  There have been people who claim there will be an upgrade path.  No official word since the "no", which may indicate there is no path, or may just be par for the SS course.

A tech company's article elsewhere indicated SS2 has a one-time-only programmable chip, therefore, no upgrade path.  And had there been one, Simplisafe could have, and should have, in 2016, fixed the vulnerability.  I think it's pretty obvious they had no intention of doing so, until SS3.

Any system can be hacked. Make sure your doors and doorframe are solid and reinforced, and that you have quality locks installed. Security systems are great, but you need to do more. https://www.locknmore.com/3-steps-burglar-resistant-doors/

SS has a new system, SS3, which has 'all signals encrypted'.  It has not been hacked, at least not yet.

@sfink16, no they do not. I think they should, but they must think otherwise.

No, it was not fraud to not encrypt the signals, it was a design choice, eventually proven to be a bad one.  Which they fixed, as they said they would.  But no, they did not provide an upgrade path as they said they would.

So it's "safe" to now use the SS yard signs and decals? That is, the hacking issues have been resolved in the SS3? Just don't know whether to use the SS signs/decals or put up Brinks signs instead (or not...)... Any updated info would be appreciated.

We don't know.  They did encrypt the signals, but there is no verification that the disarm signal now "rolls" (varies for each issuance).  If the disarm signal is always the same, it can be recorded and replayed, which was the original weakness.

Even if the problem was completely fixed, I'd still not have SS signs.  Why give the bad guys any help at all?

Shorter answer: Don't advertise your alarm system. In fact, use ADT signs and window stickers.

If perps don't know what you have, they can't attempt to hack.

I understand why security companies insist putting signs on windows/yards: Advertising.

Unfortunately (and ironically nowadays), end users should realize this is an invitation for hacking, when they think this is a deterrent, with this (now) false sense of security. Not sure why security systems companies don't understand this.

By posting in plain sight the system you have, you just invited someone to hack it.

Keep it hidden, that's the ultimate security.

Actually I wish SS wouldn't paste their name on the new doorbell, and I wish all manufacturers' doorbells looked the same.

But a sign in your yard is an invitation (to a challenge for some).

And if you have the $24.99 monitoring and use the phone app to arm and disarm then no need to worry about codes that "roll" as nothing is being transmitted from keypad.

The chances that a criminal will invest the cost and time to hack your budget home security system so they can break into your middle-class house and steal a little loose cash, some chintzy costume jewelry and/or a half-empty bottle of Vicodin are very low.  If your last name is Rockefeller (or Bezos), or you are safeguarding classified information, you should be using (and able to afford) a much more sophisticated system.  If you're an average Joe, don't worry about it.  After years of use by millions of households, I have yet to see any reports of burglars or home invaders actually defeating one of the wireless home security systems by hacking or jamming them.  Technically possible, yes, but not worth the effort.  It's sort of like people worrying about their door lock getting picked when it's many times more likely a burglar will simply kick it in.

I came across this one:
https://www.youtube.com/watch?v=UlNkQJzw4oA

This is simple signal jamming system - just like cellphone or radar jammers. I wonder if Simplisafe has any solution? (or any other alarm company that uses wireless sensors).

They do have some "frequency interference" detection capability