Why are plus signs (+) suddenly showing up in Google Analytics organic search keywords reports?

[RCF]

Since June 13, 2013, the number of organic search queries containing a plus sign (+) has gone up over 1,000% compared to the previous period on my site in Google Analytics.

These plus signs appear to be taking the place of spaces in these search queries (i.e. "word1+word2+word3").

This appears to be almost (or completely) Google organic traffic, not other search engines.

Since I highly doubt searcher behavior would change so suddenly, I'm trying to figure out why Google is replacing spaces with plus signs.

Is anyone else seeing this? Any ideas?

[RCF]

Thanks for the regex insight, Mark.

I haven't been able to find a common denominator yet, but I'll keep looking.

[Mark_Ginsberg]

Not sure why this is growing recently, but when learning regex for Google Analytics with the awesome LunaMetrics regex guide, I remember coming across the need to write brand names for advanced segments and to cover the possibility of two words being written with or without a space. Don't remember exactly where I saw it, but since then I've been writing them this way (\s|+), if I were writing seomoz for a brand advanced segment, and wanted to cover seo moz and seomoz, I would do it seo(\s|+)?moz

Basically, the regex for a space is \s, but analytics sometimes treats spaces as +, so to cover your bases, you do it either with a \s or a +.

My point is, this has been around for a while - not sure why the sudden increase, but I know this has been around for quite a bit. Maybe try drilling down a bit and seeing if you can find a common denominator here about the traffic and what is causing it.

Mark