So what is a grocery store blocker you ask?
This is a person who blocks your access to something with their cart and doesn’t allow you to get something … until they are done. Now, I’m not talking about me being impatient waiting for someone to move so I can grab something. No, no, no. I’m talking about the person who deliberately and strategically uses their cart to block you.
Let me give you an example …

I wanted to get some steaks from the meat cooler. That’s the open topped refrigerated section that the prepackaged meat is sitting in (seen above). I go over and there is an asshole who has his cart length wise against the cooler, so the packages are out of my reach unless I’m going to be rude and reach across him … and for once … I’m trying to be polite. He is picking up every fucking package and inspecting it. He senses my impatience due to the death stare I’m now giving him and the intentional heavy sighs I’m emitting. He senses that I’m past being polite and I’m about to reach across and grab a package. He then starts piling the packages close to him … almost guarding them because he doesn’t know what package is going to be the “one” and doesn’t want me to grab any until he’s viewed them all. He quickly decides this package is the best one and puts it in his cart and scurries off. He left all the packages he fucked with against the edge in disarray. What a dick!
Another type of blocking …

A person who leaves their cart in the middle of the aisle while they walk off to look at something. Then when I come down the aisle, I have to patiently stop and wait for them to come back and move their cart … or I have to move it. I always pick the latter! I grab their cart and abruptly move it, frustrated by what an inconsiderate asshole this person is. This usually elicits a look of disbelief that I had the nerve to touch their cart. Uh … you better fucking believe it! Next time, don’t leave your cart in the middle of the fucking aisle asshole! Do you think you’re the only one shopping here!?
And the stores can be guilty of blocking also …

Quite honestly, I believe this is the worst. You are choosing now to stock your fucking shelves! Seriously!? You couldn’t do it when the store was closed!? And the employees never have their shit off to the side of the aisle. No! They always block almost an entire entrance to an aisle so you have to go all the way around to the other side to get what you need down the aisle. They bring huge carts out and won’t move them for you to get by. You do want my business, right!? Stock that shit after hours!