I realized just now that a lot of people outside Poland don't know about the mayonnaise conflict. It's an ongoing feud between fans of Winiary (currently a brand owned by Nestle,) and Kielecki (manufactured by a co-op).

The feud reintensifies during holidays (Christmas and Easter) when the vegetable salad is usually made in large quantities. The seriousness is at the level of Amiga vs. C64 feud. So some people take it too seriously, some don't so we get this:

@makdaam Mało kto z uczestników tego konfliktu zdaje sobie sprawę, że najlepszym majonezem na świecie jest majonez świdnicki ;)
@PabloveSky That's not true. The best one is home made, based on the grandma's recipe.
@makdaam tylko jak pogodzić przepisy dwóch babć, gdzie jedna do majonezu nigdy jajek nie dodawała, za to druga babcia mawiała, że bez jajek nie ma majonezu ;D
@PabloveSky Blenderdome.