In general, I'd say the main issue with "identify this cipher" questions is that they're often either unanswerable, arbitrarily made up (i.e. homework or crypto puzzles) or, occasionally, both.
That said, I don't think all such questions are bad, but the set of circumstances where they can be good is limited. Specifically, any modern secure cipher, with an unknown key and no identifying metadata, will produce ciphertext that is effectively indistinguishable from random. Thus, for a cipher identification question to be answerable, either:
the ciphertext needs to have attached metadata identifying the cipher,
the code to implement the cipher must be known, and supplied,
the key (and any processing applied to it before encryption) must be known, or
the cipher must be somehow insecure: either old (Caesar, Vigenère etc.), deliberately designed to be breakable (crypto puzzles) or just used inappropriately (e.g. a block cipher in ECB mode, or with a reused key+IV).
Arguably, case #1 really belongs on Stack Overflow (although one could argue for the topicality of parsing standard metadata formats here), while cases #2 and #3 might fit better on Reverse Engineering. This leaves only case #4, and even there, crypto puzzles are often poorly suited for this site (some may be on topic at Puzzling), and likely to be closed as "requests for analyzing or deciphering a block of data". (The exceptions tend to be questions asking about cryptanalytic techniques for solving such puzzles, with actual ciphertext given only as an incidental example, if at all.)
As for your specific question, it does seem to fall under the "somehow insecure" category, and thus be potentially answerable. Indeed, the obvious answer (bitwise XOR with a constant key) has already been given in the comments (although, as Henrick notes, there's not enough information in the question to definitively rule out other possibilities).
What's somewhat unclear to me is whether this is actually the answer you want. If it is, I'd be inclined to reopen the question, perhaps edit it a bit to remove irrelevant distractions, and let someone turn those comments into a proper answer. It probably won't ever be the greatest question on this site (for one thing, its rediscoverability via Google will be rather poor), but it should be OK.
That said, the XOR answer seems so obviously trivial that I'm not 100% sure if that's really what you're asking about. If not, you might want to edit your question to clarify it.